The levels of physical and motor ability for improving fundamental motor performances in children and youths need to be investigated for the development of sound PE program. PURPOSE To determine the levels of test performance of physical fitness for improving mat exercise performances in children and youths. METHODS A questionnaire on mat exercise performance and physical fitness measurements including Japan Fitness Test were carried out with 5086 girls and 5639 boys in elementary and secondary schools, aged 6 to 18 years old. Improvements of 5 kinds of mat exercise were investigated on the 5 questionnaire items with 2 options. Muscle strength, muscle endurance, muscle power, flexibility, agility, sprint and aerobic endurance were measured by using 7 performance tests of grip strength, situps, standing long jump, sit and reach, lateral side step, 50m-dash, and 20m-shuttle run for children and youths. Applied tree-based method by CART analysis of data mining technique utilized to analyze the levels of physical fitness test performance for improving their mat exercise performances on application software of Answer Tree release 3.1 J. Depth of the trees was set in stage 2. Gini-index was used as the evaluating function for classification by the tree. RESULTS The split values of the first and second split variables of the classification tree model of each mat exercise item on physical fitness tests were obtained by CART analysis. The classification rates of the first split variables of all mat exercise items ranged from 64% to 78%. The estimated error rates for ranged from 4% to 38%. The physical fitness performance level for improving rate 83% of split roll of mat exercise was 35 reps in 20m-shuttle run test and 16 kg in grip strength test for girls, and in boys 38 reps in 20m-shuttle run test and 8.3 sec in 50m-dash for improving rate 84%. CONCLUSIONS The levels of physical fitness test performance for improving mat exercise in children and youths were statistically determined.