In practice, many people who have obtained foreign citizenship have managed to keep their hukou in China, Jin said.
China's Nationality Law, which came into effect in 1980, said China does not recognize dual nationality. When Chinese citizens take the nationality of another country, they must renounce their Chinese citizenship — and vice versa — but the stipulation has been criticized as being too harsh and may drive away overseas talents.
A report issued in 2011 by Huaqiao University, a subordinate college of the State Council's Overseas Chinese Affairs Office, said the number of overseas Chinese has topped 45 million.
Gao Siren, director of the Overseas Chinese Affairs Committee of the National People's Congress, said overseas Chinese have long called on the government to streamline the paperwork for them to return to China by issuing more "green cards" or lifting the ban on dual nationality.
Liu Guofu, a law professor with Beijing Institute of Technology, said the Immigration Law should be designed to improve the competitiveness of a country, and its limits on population mobility, especially on top-notch experts and overseas Chinese, may diminish China's attractiveness.
South Korea last year amended its law to allow overseas South Koreans, immigrants married to South Koreans and international talents to hold dual citizenship, after Vietnam made similar changes in 2009.
Liu said more than 90 countries and regions currently recognize dual nationality.