The main purpose of this study was to realize the relationship between exercise behavior and the performance of different exercise types on physical fitness, and their differences. Four hundred and sixty four randomly-selected freshmen of 2002 from 10 classes at Kun-Shan University of Technology were included in this study, 241 of whom were male, and the rest were female. The collected data were statistically analyzed using T-test, Chi-square test, and One-way ANOVA with SPSS 10.0 Edition software to indicate each index's difference between groups. We obtain conclusions as follows: 1. The physical fitness of the school's freshmen compares unfavorably with that of those at the same age, especially for 1600/800~meter run and walk. 2. Regarding the differences of the freshmen's exercise behavior, males have a significantly higher level than females on weekly exercise frequency, exercise duration for each time, and fatigue level after each exercise. In terms of exercise type, males prefer ball sports, while females prefer aerobics and leisure exercises. 3. Male freshmen of the school participating in ball sports have better fitness performance on standing broad jump and 1600-meter run and walk than those in other exercise types. In addition, regarding the fitness performance of the female freshmen on exercise type, ball sports participants have higher Body Mass Index (BMI) than leisure exercise participants, while aerobics participants have better performance on 800-meter run and walk than ball sports participants.