Coping with problems brought by a large population has become an unavoidable challenge facing megacities like Beijing, said a deputy to the National People's Congress (NPC) on March 5.

Ouyang Song, a director at the Party History Research Center of the CPC Central Committee, said megacities' development cannot be separated from migrants. But the large inflow of migrants in recent years has exerted great pressure on cities' resources, environment, education, medical treatment, and social welfare.

Beijing's permanent population reached almost 20.7 million by the end of 2012, and about 37 percent-7.74 million- are non-native residents who live in the city more than half the year, compared with 18.9 percent in 2000.

To cope with the population pressure, Beijing must transform its economic development model, decentralize downtown functions, strengthen management of non-natives and issue a residence permit policy as soon as possible, said Ouyang.