Research Findings: A growing number of young children encounter group learning environment for the first time when entering preschool at age 3, yet their parents and teachers have no means to discern whether they are ready for this challenge. To address this uncertainty, this study developed and validated the Chinese Preschool Readiness Scale (CPRS), which assesses children's readiness for successful adjustment to preschool. The scale was validated through EFA in Study 1, with 29 teachers who rated 288 children. The scale was further validated by ESEM and confirmatory factor analysis (CFA) in Study 2, with 46 teachers who rated 765 children. A five-factor CPRS was determined: self-care abilities and emotional maturity, cognitive and communications skills, social competence, learning dispositions, and classroom rules. The construct validity and internal reliability were satisfactory. Its concurrent validity was also established: (1) the CPRS scores were positively correlated with parent-rated self-regulation and (2) the social competence domain of CPRS was positively correlated with sensitive-cooperative behaviors and negatively correlated with anxious-withdrawn behaviors. Practice or Policy: The results supported further development and use of the CPRS to monitor children's development upon entry at preschool. The findings also highlighted the need for more research on preschool readiness.