Sun Yingjie, winner of the women's marathon event at the ongoing National Games, tested positive in a doping test.
The test was carried out after the women's 10,000m race during which Sun won a silver medal. As a result of the violation, Sun was stripped of the silver medal.
Further investigation will be carried out and sanctions followed accordingly, said the State General Administration of Sport.
26-year-old Sun Yingjie finished third in women's 10,000m at the 2003 World Championships in Paris. She also won two gold medals in women's 5,000m and 10,000m at 2002 Asian Games