China's social security fund manager says the investment return for 2015 was 15 percent, up from 11 percent in 2014.
Data shows the National Council for the Social Security Fund earned 230 billion yuan or 35 billion U.S. dollars from all investments last year.
The rate of return outperformed the average return of 8.4 percent, for the period from the fund's establishment in 2000 to 2014.
The fund is designed to serve as a solution to the problem of China's aging population, and a strategic reserve to support future social security expenditure.
It is invested in a variety of financial products both at home and abroad, including fixed-income assets and stocks.