As more than nine million students finish taking the national college entrance exam, or gaokao, they now become the target of businessmen and the so-called "after-gaokao economy".

A candidate is busy preparing for gaokao, May 23, 2016. [Photo/IC]

Cram schools begin to snatch gaokao students who are unsatisfied with their exam score and want to get better marks.

A teacher, surnamed Zhang, at a famous institute in Beijing, said that they will set up more than a dozen review classes this year and place students in basic, advance or key classes based on their exam scores.

"Though we place them in different classes, the tuition fees are same at about 70,000 yuan ($10,647) a year including accommodation," said Zhang.

A teacher, surnamed Hao, in another cram school said that they have 20 years of experience in running review classes. About 50 percent of their students have got admission in first-class universities in recent years.

They charge more than 60,000 yuan a year in tuition fee and for some students who require one-to-one class the fee goes up to 300,000 yuan ($45,630).