Most of the existing literatures classify urban integration into four dimensions: economic integration, social integration, psychological and cultural integration. Economic integration measures migrant workers’ income and the gap with urban population, social integration measures migrant workers’ job stability, working environment and social security, psychological integration measures migrant workers’ happiness, income satisfaction, life stress and living faith, cultural integration measures migrant workers’ community involvement, policy concerns, social interaction and language acquisition

But in specific analysis, some scholars think that the economic and social integration is easier to measure, and therefore their mainly focus on the economic and social integration [5] [6] . Also some scholars suggests that psychological and cultural integration is more important, so they emphasis on psychological and cultural integration [7] . Therefore, this paper also follows the previous practices that study the four dimension of urban integration: economic integration, social integration, psychological and cultural integration.

According to the junctions tightness of the relationship between individuals, social capital can be classified into strong and weak social capital [8] - [10] or original and new social capital [11] , and according to the openness and closeness of social network, social capital can be classified into integrated social capital and bridged social capital, the former is formed by closed network which consists of geographical and kinship and the later emphasizes the flow between different social groups caused by cross coupling [12] .

Both types of social capital play an important role on the process of urban integration of migrant workers, but the influence may be different, migrant workers’ integrated social capital mainly relies on the social network of home level, networks which consists of relatives and friends from their home can help promote their wage and find a new job in the city, but if this kind of social network can help migrant workers integrate into the local community and the city needs further study. On the other hand, some related studies [13] suggests that as to promote the migrant workers’ income, bridged social capital plays a more important role than integrated social capital. Then in the level of urban integration, whether these two social capitals have different impacts? Thus, in our empirical research, we study the influence that the two different social capitals have on the degree of urban integration.

According to existing studies and combining with our survey data, we classify social capital into integrated social capital and bridged social capital, the social capital formed by closed social network that consist of geographical relations and kinship is defined as integrated social capital, and the social capital formed by open social network that is derived from the flowing between different groups is defined as bridged social capital [13] . Integrated social capital can be classified into two categories, one is the relatives and friends that live in the migrant workers’ home, the other is the relatives and friends living in the city, and bridged social capital is the relatives and friends living in Guangzhou. Specific definition is in Table 1.

This paper measures the degree of urban integration of migrant workers in Guangzhou 2014, and urban integration includes four dimensions: economic integration, social integration, psychological and cultural integration, then we get the total degree of urban integration by adding the four dimensions. The statistical data is in Table 2.

The descriptive statistical analysis of the main variables shows that migrant workers’ ability to integrate into city is very poor as the income gap with the Guangzhou urban residents is large. as to the age, The average age of migrant workers is 30.5 years old, and as to the gender ratio, male migrant workers accounted for half. The average time migrant workers living in Guangzhou is 9.7 years, and more than half of migrant workers are already married, as to the education level, most migrant workers are high school graduates, which accounting for 48%,while only 7.5% of migrant workers are primary school graduates, it suggests that migrant workers’ human capital has been greatly improved. In the total sample, few migrant workers are self-employed and most migrant workers are from Guangdong Province (Table 3).

Table 4 suggests that the total number of relatives and friends visit in Chinese New Year do not have significantly effect on urban integration, but the number of relatives and friends from their home and the relatives and friends living in the city have significant positive impact on urban integration, and the influence of the relatives and friends living in the city is bigger than the relatives and friends from their home, whether migrant works have relatives or friends living in Guangzhou do not have significant effect on integral urban integration, Social capital of migrant workers can indeed facilitate their integration into the city as a whole, and different social capital have different effect on migrant workers’ integral urban integration, migrant workers’ integrated social capital have significant positive effect on urban integration, and bridged social capital do not have significant effect. But it does not mean bridged social capital does not have effect on urban integration of migrant workers. This is probably that bridged social capital mainly promote psychological and cultural integration. This requires us to distinguish between different dimensions of urban integration.

The regression results in Table 4 shows the effect social capital have on the four dimensions of urban integration: economic integration, social integration, psychological and cultural integration. And conclusion finds that only the relatives and friends from migrant workers’ home have significant positive effect on economic integration, economic integration suggests that migrant workers can base in the city, and have a stable job and income. migrant workers’ traditional social capital can help them find career opportunities, provide information and direct financial assistance so as to promote their integration into the city at the level of economic. But we also find that the traditional integrated social capital have significant negative impacts on psychological and cultural integration. The explanation may be that the more social ties migrant workers have with the relatives and friends from their home, the reliance is more serious migrant workers have on their rural home. And it is not conducive

for migrant workers to integrate into the city at the psychological and cultural level. On the contrary, the more friends and relatives living in the city or Guangzhou migrant workers have, the contact migrant workers with the city is more closely. Then the identity and participation can be improved and so do the urban integration at the psychological and cultural level. The empirical regression results also confirm this point that bridged social capital can significantly promote psychological and cultural integration. At the same time, further analysis of the data suggests that bridged social capital do not have significant effect on economic and social integration (Table 5).

Using the field survey data of ten districts in Guangzhou of 2014, this paper estimates the degree of urban integration of the migrant workers in Guangzhou. Conclusion finds that: social capital of migrant workers has

significant impact on their integration into the city, and different types of social capital have different impacts on the different dimensions of urban Integration of migrant workers. Social capital into integrated and bridged social capital and urban integration are classified into four dimensions: economic integration, social integration, psychological and cultural integration. Conclusion finds that migrant workers’ integrated social capital mainly promotes the integration of economic dimension and has negative effects on the integration of psychological and cultural dimension. However, migrant workers’ bridged social capital can significantly promote psychological and cultural integration.

In order to promote urban integration of migrant workers, the government should give appropriate guidance and support and note to enhance migrant workers’ social capital; specifically, government should provide vocational skills training and expand more employment channels for migrant workers to promote migrant workers’ human capital. On the other hand, policy makers should offer more opportunities and communication platform for migrant workers with household living in the city so as to promote migrant workers’ social capital.