BEIJING — On the last day of August, Xiong Jing and two friends shaved their heads in Beijing to protest a growing trend in Chinese universities in which women increasingly must score higher than men to get in and face unofficial but widespread gender quotas that favor men.

The three women were outraged when the Education Ministry said in August that the practices were in the “national interest.” They conducted their action in the privacy of an apartment, since any kind of protest in the Chinese capital was considered risky. The day before, in the relatively freer southern city of Guangzhou, four other women shaved their heads in public and gave the Education Ministry a “zero” score for fairness.

In all, Ms. Xiong said, about 20 people around China — mostly women but some sympathetic men, too — shaved their heads to protest the rules. Their protest was inspired by three female artists who shaved their heads in public here in March to call for greater women’s rights.

“The Education Ministry’s response made us really angry — it’s just such a pity,” Ms. Xiong said in an interview in Beijing, her normally shoulder-length hair reduced to stubble. “It’s illegal too. The Education Law forbids discrimination on several grounds including gender. And the Education Ministry is allowing it.”