Chinese high school students have the longest study hours compared to their peers in Japan, the U.S. and the Republic of Korea, a survey conducted by the four countries said.

    The survey, released by the China Youth and Children Research Center (CYCRC) on Monday, was jointly conducted with institutions in the four countries in September-October of 2008. It covers nearly 4,000 students in senior high schools and vocational high schools in the four countries.

    About 78.3 percent of Chinese students said they spend more than eight hours at school and 56.7 percent said they study at least two more hours each day at home.

    By contrast, only 24.7 percent of their peers in the U.S., 20.5percent in Japan and 15.4 percent in Korea study more than two hours after school.

    Around 60 percent of all students surveyed said their burden for studies were the heaviest, however, the Japanese felt their burden was the worst with respondents reaching 79.2 percent.

    Among the five biggest headaches for young people in the four countries were: over-scheduling ranked first, followed by a monotonous leisure life, unsatisfied appearance, little time for exercise and making friends, and no spare money.

    "Moderate study pressure can better drive students to develop, however, too much will squeeze their development space, and can even cause harm to their physical and psychological health," the survey said.

    "Balancing their studies and all-round development is a very important task," it said.