Anti-doping officials unearthed 450 doses of EPO, testosterone and steroids during a raid on a Liaoning athletics school's training camp earlier this month, according to state media.
China is cracking down on the use of banned substances to avoid any embarrassment when it hosts the 2008 Olympics and state sports officials have been unusually quick to reveal details of the August 8 raid.
A spokesman for the Chinese Olympic committee's anti-doping commission told Xinhua news agency that the raid, prompted by a tip-off, uncovered doping of athletes as young as 15 at the Anshan Athletics School training camp in Harbin.
Zhao Jian said anti-doping officials had found 25 bottles of erythropoietin (EPO), nine bottles of testosterone and 17 bottles of steroids in a room where school staff were caught injecting 10 students with drugs.
A further 275 doses of EPO and 124 doses of steroids were subsequently found in a refrigerator in headmaster Shao Huibin's room.
The students, aged from 15 to 18, were preparing for the provincial games. Their teachers and coaches now face criminal prosecution under China's 2004 anti-doping code.
Liaoning is known for producing world class athletes but has previously been embroiled in doping scandals.
Controversial athletics coach Ma Junren, who was based in Liaoning, produced a crop of world class distance runners known as "Ma's Army" in the 1990s.
Ma always maintained his athletes broke world records and won world titles with the help of nothing more than turtle blood, caterpillar fungus and a gruelling training schedule.
Just before the 2000 Olympics in Sydney, however, Ma and six of his runners were dropped from the team when blood tests revealed abnormal results.
Xinhua reported that Ma was once a coach at the Anshan school, which was founded in 1992.
Another sports school in Liaoning provincial capital Shenyang was caught doping students in 2002, while Liaoning distance runner Sun Yingjie was banned for two years after testing positive for the steroid androsterone.