China's anti-doping authorities Wednesday said eight athletes had tested positive in the second quarter of the year, including one through the biological passport.
By far there have been 12 doping cases this year, leveling the total of last year.
China's Anti-Doping Agency (CHINADA) said the rise in number of positive cases may have something to do with the approaching Chinese National Games.
"The number of positive cases has largely increased compared with that of last year, which sent us a warning," said CHINADA head He Zhenwen.
"There always will be someone who risks doping for unfair advantage when the return is lucrative," said He. "History taught us that the national games could well be the reason for cheating."
The national games, inaugurated in 1959, originally with an aim to promote sport and encourage the mass public to build up their bodies, drew teams representing provinces, municipalities and autonomous region.
The national games program includes most Olympic sports. Good results at the games are viewed as work achievements of provincial sport bureaus and usually bring medal winners even higher rewards than international titles do.
This year's national games will be held in northern province Liaoning on Aug. 31 through to Sept. 12.