The binary division of China's urban labor market has resulted in differences in improving mechanism of employment quality for workers. From the perspectives of capital and occupational mobility, this study employed the data from the China Labor-force Dynamics Survey ( CLDS ) to examine and test the factors that affect workers' improvement of quality in different labor markets. The study found that knowledge human capital, weak relational social capital, and political capital of cadres have a positive effect on improving employment quality for primary labor market workers. For secondary labor market workers, employment quality can be improved by enhancing knowledge human capital, technical human capital, weak relational social capital, and political capital of cadres. As primary labor market workers improve their employment quality through active and self-initiated occupational mobility, secondary labor market workers can improve their employment quality by increasing their frequency of occupational mobility. Capital factors do not have a restraining effect on the improvement of employment quality through occupational mobility for primary labor market workers, but to a certain extent, they do have an inhibitory effect on secondary labor market workers. Thus, it is necessary to fully understand the demands of workers and the real employment situation to help the employees in the secondary labor market increase the investment and accumulation of human capital, social capital and political capital so as to improve their employment quality.