In 1998,the number of suicides increased sharply among men in their 50s to 60s in Japan, leading to a rate of more than 30,000 suicides a year. Although more than 10 years have passed since then,there are no signs that this is improving. The number of suicides increased not only among middle-aged and elderly people, but also across all age groups, including those in their 20s. Reducing suicides among university students aged around 20 years has been a top priority for those involved in mental health in universities. In this article, by analyzing survey results spanning the 21 years from 1985 to 2005, I clarified the characteristics of Japanese university students’suicides and identified risk groups. I also investigated background factors to help identify and promote preventive measures. The subjects were undergraduate students at Japanese national universities in either 4 or 6-year programs, and the data were annually collected by means of questionnaires from universities that participated voluntarily. Starting from April 30 of a specific year, the following items were surveyed : cause of death of students who died during the year, what academic year they were in, their sex, the major they studied,what month of the year they died,the method of suicide if applicable,any diagnosed psychiatric disorder,and the presence or absence of involvement of the university health center. The survey results of the 21 years from 1985 to 2005 were gathered, and I statistically analyzed the longitudinal changes in the suicide rate over this time period and the correlation between the suicide rate and sex, major, academic year, psychiatric disorders, methods of suicide, etc., using the chi-square test and residual analysis. Altogether, 7,350,496 students were surveyed, and 987 of them had committed suicide. Comparison of the causes of death among the 2,706 students during the 21 years showed a significantly higher incidence of suicide and accidents than any other causes of death, followed by death due to disease. Both the total death rate and deaths due to accidents decreased, but the suicide rate of university students in this sample did not change. During the bubble economy years from 1988 to 1991,many more deaths in this age group were due to accidents compared to suicide,but,since 1996,the suicide rate has been consistently higher every year, and has remained the main cause of death throughout the economic recession. In terms of sex, men were significantly more prone to commit suicide, as was the case throughout in other age groups. Concerning the sex and major, the suicide rate was higher in men who majored in medicine, the humanities, and dentistry. As for the academic year of study,at universities with 4 or 6-year programs,the 4th year and holdover（taking longer than the usual time for a course）students in the 5th and higher, or 7th and higher years,respectively,showed a high suicide rate. Therefore,we can say that holdover students were a high-risk group for suicide,and attention should be paid to them as well as high-risk groups of male medical, male liberal arts, and male dentistry students. The university health centers were involved with only 19% of students who committed suicide. Only 19% of students who committed suicide had received a psychiatric diagnosis, mostly F3 and F2. Most students who committed suicide had thus not been diagnosed or treated. For the method of suicide, hanging and jumping from a height were frequently seen among them. A clue to prevent suicide among university students was gleaned from these results. It is imperative to take action through informing students of campus mental health and suicide prevention resources and to provide educational programs on suicide prevention for students, professors, and other staff. Additionally, the reforming educational structures and campusbased administrative organizations is necessary to some extent. This is especially true of medical schools, where a systematic change in education is needed.