BEIJING, Jan. 4(Xinhuanet)-- The population in the Chinese mainland is expected to reach 1.3 billion on Jan. 6, according to a prediction the National Statistics Bureau(NSB) released Sunday.

The day has been successfully postponed for four years with the effective birth control policies in China, the NSB source said.

China has made persistent efforts to slow its population growth over the past 30 years and succeeded in reducing the birth rate, said an official of the State Commission for Population and Family Planning(SCPFP).

The birthrate dropped from 21.06 per thousand in 1990 to 12.41 in 2003, while the growth rate went down from 14.39 per thousand to 6.01.

However the country would face new and severe challenges with its population climbing to the level of 1.3 billion, the SCPFP official said.

Although the population growth rate has been reduced, the actual increase is still huge. Also the country is expecting a peak in the number of elderly and migrant population amid growing imbalance in gender proportions among newborn babies, the official said.

The pressure on employment also grows with the increase of population, he added.