Nearly 600,000 foreigners were living on the Chinese mainland at the end of 2010, results from the sixth national census released by the National Bureau of Statistics (NBS) on Friday showed.

It is the first time the country has included foreigners who would stay on the mainland for at least three months in its once-in-a-decade population census, as "they've been playing an increasingly important role for the nation's social and economic development", said Zhai Zhenwu, dean of Renmin University's school of sociology and population.

According to the census, the top three home countries of the foreigners on the mainland were the Republic of Korea (ROK), the United States and Japan.

Among them, 56.62 percent, or 336,245, were males and 43.38 percent, or 257,587, were females, it showed. Business and study are major reasons bringing them here.

"The census results would help decision-makers with evidence and guidance when it comes to form new policies better serving foreigners' stay, employment and migration on the mainland," Zhai noted.

Previously, Xinhua reported that Chinese government officials and academics had started planning the country's first draft immigration law to better manage the increasing number of immigrants.