A woman's rights activist is claiming possible sex discrimination in terms of the male-female ratio of admission rates to higher education institutions.

Lü Pin, program director of Media Monitor for Women Network, sent a letter Monday to the Ministry of Education, asking the  ministry to reveal what majors it allows to have different ratios between genders. She is also asking it to explain on what grounds the policy is based.

Some universities accept male students who have attained a lower gaokao (national entrance examinations) score than female students, Southernnews.com website reported on Sunday. Eight out of 28 colleges had different standards for males and females, the report said.

"I didn't realize there is still a 'gaokao score gap' for university entrance until I saw the published admission scores," said Lü. 

Female applicants to the China University of Political Science and Law must score 40 gaokao points higher than males, while females applying to Beijing Foreign Studies University need 19 more points.  

"The gaokao score is supposedly the only standard for competing for college places, so how come gender is also considered? It is ruining the equal rights to an education," said Lü.

A teacher surnamed Tang, from the School of Foreign Languages at the Communication University of China, said adopting different score standards is an attempt to maintain a gender balance.

"It's more like 20:1 between female and male students in the faculty, but on the other side, employers more favor male graduates, so the school has to keep the balance to meet the demand," said Tang.

"Plus, young people also come to college for social skills, so it's not good to have only one sex on the campus," said Tang.

In schools specializing in foreign languages, the student body is more than 70 percent female, the Beijing Times reported Wednesday.  

However, as many as 91 percent of female undergraduates in a survey by All-China Women's Federation in 2011 said they have encountered apparent sex discrimination on the employment market, according to a Xinhua News Agency report on April 23.

"Maintaining a gender balance is an excuse. I don't see them lowering the scores needed for female science majors," said Lü.

"I hope the public will join me in fighting for equality," she said.

The education ministry did not reply to faxed questions Wednesday.