The purpose of this study was to investigate the relationship between the Penn Interactive Peer Play (PIPPS-HK) and the Preschool Play Behavior Scale (PPBS-HK) to establish concurrent validity of both scales. A total of 1,622 children age 3 to 6 and 152 teachers in 10 kindergartens (about 160 students and 15 teachers randomly selected from each kindergarten) participated in this study. The PIPPS-HK correlated well with the PPBS-HK, providing further evidence of each measure's validity. However, a different meaning of social withdrawal behavior in PPBS-HK was found in the two measures. The emic concerns regarding social withdrawal need to be further identified in the Chinese cultural context.