Teachers should not let parents grade or check students' homework, the Ministry of Education said on Tuesday after several local education authorities banned the practice following fierce criticism from parents.

Lyu Yugang, director of the ministry's department of basic education, said teachers should not assign any homework to parents or assign homework that is so demanding that only parents can finish it on their children's behalf.

"They should also not ask parents to grade or check students' homework and I should stress that this requirement should be delivered to all teachers," he said at a news conference.

Teachers should grade students' homework themselves, give timely feedback and answer their questions, he said, adding that they should not assign punitive or repetitive homework.

Schools should limit the amount of homework and make sure its difficulty does not exceed the standard for the curriculum, he said.

Students in the same grade should have the same homework and there should be coordination between teachers not to assign too much homework, he added.

Ye Yuting, mother of a first grade student in Beijing, said she strongly supports not letting parents grade homework.

"Currently, the school asks me to supervise my daughter's homework, grade it and sign my name afterward," she said. "There is no punishment from the teachers if I refuse to do so, but there is peer pressure from other parents.

"It is a daily task that requires lots of time and effort, especially for parents like us who both need to work."

Ye said she hopes her daughter's school can quickly follow the ministry's new requirement and liberate her from the burden.

Yu Fengyi, father of a second grade student in Yueyang, Hunan province, said he also has to grade his daughter's homework.

"I do not understand why a 7-year-old needs to do so much homework," he said. "Sometimes she could not finish it until after 10 pm. I even want to do it for her."

Teachers believe parents should participate in children's education and grading homework is a good way to make teachers' jobs easier, he said.

Grading homework is clearly the teachers' responsibility and parents are just afraid that the teachers might not treat their children fairly if they refuse to do it, he said.

Yan Yun, a teacher at a primary school in Wuhan, Hubei province, said her school does not allow parents to grade homework but some parents have voluntarily done so.

Primary school homework is not difficult and students are supposed to be able to finish it themselves, she said, adding that too much homework help from parents will make students dependent on them.