Education authorities have urged local schools not to flout regulations after finding violations of the rules at some private schools.
The Shanghai Education Commission said violations included reducing or neglecting Chinese courses, such as history, politics and morality, and even Chinese itself, and in some cases offering international courses that bypassed required teaching.
The commission said it would survey private schools providing international courses and work out rules to bring them into line with the city's educational requirements.
"Schools can introduce international courses into their teaching, but should not replace the basic Chinese courses because they are a requirement of our compulsory education law," said an education commission official surnamed Zhu.
"Textbooks should be approved by not only the schools, but also the district education bureaus and the city's education commission to prevent questionable content," she added.
Other violations by schools included recruiting students in advance of the schedule set by the commission.
There are four types of schools in Shanghai — public, private, international, and those co-operating with foreign countries.
According to the regulations, foreign capital can only be used to run kindergartens or high schools in cooperation with local educational institutes, but not primary and middle schools, a period known as "nine compulsory education years."
Local public and private schools covering this period are not allowed to adopt solely international courses unless they are incorporated in the international divisions of some schools that were set up with approval from the commission and only admit international students.
Some parents are wary of what might result.
"As schools are asked to ensure enough time for Chinese courses, the international ones might be reduced," said a man surnamed Gong.
"It might have adverse influence on students who have decided to study abroad in the future and are taking international courses to better connect with international education system, Gong added.
His son is a fourth grader at a local bilingual school.
