Abstract: The article aims to explore the differences in physical fitness of college students with different body mass indexes. The freshmen of Fujian Business School in 2019 were selected as the research object, and physical fitness tests were conducted during physical education class. The test included body mass index, standing long jump, sitting forward, sit-ups, pull-ups, and endurance running. As for collected data, descriptive statistical analysis is performed and then single-factor variance analysis is applied to compare the differences. The research showed that college students' various physical fitness conditions performed poorly in four aspects: muscle endurance, instantaneous explosive power, and cardiopulmonary endurance. In the matter of body mass indexes, most of the students are at intermediate level, while the number of students who are too light are equivalent to the number of students who are too heavy. And the proportion of students who are too light is significantly more than that of students who too heavy. In the aspect of the difference in healthy fitness of different body mass index levels, At the moment, the moderate students are significantly better than those who are underweight or overweight in the instant explosive force project.The overweight students are significantly worse than those who are underweight and moderate in the cardiopulmonary endurance project. Suggestions are put forward to offer theoretical reference for the design and implementation of future physical education teaching.

Key words: college students, health, fitness