Their target is Ritalin, a drug used to treat Attention Deficit Hyperactivity Disorder (ADHD) containing the active ingredient methylphenidate hydrochloride.

Some parents were begging people like "Sun", whose son suffers from ADHD, to get the amphetamine-like stimulant from doctors, the newspaper said.

"I was puzzled why they needed the drug and only later understood that it was for their children preparing for the exams," Sun was quoted as saying.

"I went to the hospital four times in the past month and every time I had to cheat the doctor by saying that I had lost the previous dose accidentally."

A record 10 million high school students will sit the two-day college entrance exam from Thursday, vying for only 5.7 million of university places.

Pushy parents and grandparents are as anxious as the youngsters about the highly competitive exam, the newspaper said.

They would buy whatever tonics and drugs were promoted on TV or recommended by friends. They were also booking quiet but expensive hotel rooms near examination halls.

Medical experts have expressed concern about healthy children taking Ritalin, saying "wilful administration" could lead to poor exam performance, the Beijing News said.

Last month, authorities warned parents to stop buying a protein injection in a bid to boost the immune systems of their children preparing for the entrance exam.