This study aims to analyze the affirmative impact of PAIP(hereafter Physical Activity Improvement Program) over infant’s playfulness. Target group for this study is 5 to 6 years old kindergarten infants, and this group has been counted off for experiment by gender differences. This experiment has been conducted by 80 times, 30 minutes for 16 weeks. The result of analysis in impact of PAIP over playfulness as follows; First, there was no significant effect has not found among group, gender and period of time, but significant effects has been found in physical, social, cognitive voluntariness by interaction between group and period of time. Secondly, main effect by period of time has been significant in all of variables, and main effect by group has been significant in physical, cognitive voluntariness. But there wasn’t significant effect by gender in all variables. The above results showed that PAIP is effective to improve 5 subordinate factors which are physical, social, cognitive voluntariness, expression of joy and sense of humor in playfulness of infants.