This study was to inspect how the portfolio assessment in physical education classes affects the learning attitude and the improvement of motor skills. The experimental group of 40 students utilized the portfolio assessment and the control group of 40 students were tested with a traditional assessment. A test paper on learning attitude and a measure on assessment of motor skills was estimated of reliability and validity. After a vaulting horse-rolling instructions were practiced 11 sessions for 4 weeks that the experimental group were tested with portfolio assessment. The control group were tested with traditional assessment. Each group took a posttest about learning attitude and motor skills. The collected data through the posttest were analyzed with t-test. The findings of this study could be listed as follows; First, the learning attitude of experimental group using the portfolio assessment was better than the control group, and the difference was significant statistically. Second, the motor skills of experimental group using the portfolio assessment were better than the control group, and the difference was significant statistically.