The Ages & Stages Questionnaire: Social-Emotional (ASQ:SE; Squires, Bricker, & Twombly, 2002a), developed in the United States, was translated and adapted for use in China. Lack of valid and reliable instruments for identifying social and emotional delays in young children is a worldwide issue. Professionals in China have recently focused efforts on developing methods for early identification of social, emotional, and behavioral issues in the birth-to-5 population. Following the guidelines of the International Test Commission, the ASQ:SE was translated into Simplified Chinese (ASQ:SE-C) to collect a normative sample of 2,528 children across China. Data were analyzed to evaluate the psychometric properties of the ASQ:SE-C, using both classical test theory and item response theory, including generating cutoff points appropriate for the Chinese sample. A panel of Chinese experts was surveyed to assess face validity and estimated utility of the newly adapted tool. Discussions of research findings and implications for future studies are provided.