The migrant-worker population reached 262.61 million in 2012, with a year-on-year increase of 3.9 percent, according to the National Bureau of Statistics.

About 33.75 million of the workers migrated with their families. This marked an annual rise of 2.9 percent, the bureau said in a report released on Monday morning.

There are 169.8 million migrant workers in eastern China, accounting for 64.7 percent of migrant-worker population.

The proportion working in western China is 17.1 percent.

Guangdong province, in the south, attracted nearly 20 percent of the country's migrant workers, the report said.