The migrant worker population last year reached 252.78 million, an increase of 10.55 million from that of 2010, and the number of rural workers employed outside their hometowns stood at 158.63 million, the Ministry of Human Resources and Social Security said Monday.

By the end of 2011, about 41.4 million migrant workers have participated in pension insurance and 46.41 million have participated in medical insurance, Xinhua reported.

A total of 764.2 million people were employed in China as of the end of 2011, including 359.14 million who worked in urban areas. Of the total, about 34.8 percent worked in the primary industry, 29.5 percent in the secondary industry, and 35.7 percent in the tertiary industry, the ministry said in a statistics bulletin posted on its website.

Altogether, 12.21 million jobs were added in China's urban areas in 2011. The urban unemployment rate stood at 4.1 percent, unchanged from 2010.