China's population will be about 1.42 billion by the end of 2020, up by 45 million from 2015, according to the draft outline of a five-year plan released Saturday.

China had a population of 1.37462 billion at the end of 2015, up 6.8 million from the end of 2014, according to data released by the National Bureau of Statistics (NBS).

The country will further adhere to the family planning policy as a basic state policy, and fully carry out the two-child policy, said the draft outline of the 13th Five-Year Plan (2016-2020) submitted to the national legislature for examination.

Imbalanced sex ratio will be addressed with comprehensive measures, the draft said.

The NBS said in January that the ratio stood at 113.51, the highest among the world despite a decrease in recent years, with 33.66 million more males than females.

Reproductive health care, and maternal and child health care will be improved, and related policies will be revised to adapt to the implementation of the two-child policy, according to the draft.

Family planning service management, and birth registration service system will be improved, the draft added.

Efforts addressing an aging population and the decrease of working age population will be carried out, it said.

Zhai Zhenwu, a demographer and president of the School of Sociology and Population Studies under Renmin University, told Xinhua that the figure accurately reflected the current development trend of China's population by taking consideration of the two-child policy.

China began this year to carry out the policy that advocates one couple having two children, another major change of its family planning policy after allowing couples to have a second child if either parent was an only child in 2013.

The latest change ended the "one couple, one child" policy since the late 1970s.

The full implementation of the two-child policy will bring 3 million more people for China every year on average in the coming five years.

Zhai added that the increase will boost social and economic development by driving social consumption, but with little influence on the quality of the population as newly-born babies will be still young by 2020.

Based on the current trend, China's population peak, about 1.45 billion in number, will come around 2028, about two years earlier than the previously expected time, according to Zhai.

Zhai, one of the leading consultants for China's population policies, said that besides tougher ban on fetus gender test, the country will also take a series of measures to curb the gender imbalance, such as promoting social gender equality, protecting women in employment, and others.