With increasing numbers of women joining the workforce, there is a need for quality childcare. This project, conducted in Japan and using a large number of participants, sought to standardize an evaluation scale to measure the development of children. The development of children under six years of age (N = 22,819) who are enrolled in childcare programs was evaluated by childcare professionals. Percentiles were calculated (10th, 50th, and 90th percentile points) for each item (total 192) of six developmental subscales (gross motor, fine motor, social competence, communication, vocabulary, and intelligence development). The results supported the validity of this scale in measuring child development in Japan. (Contains 7 tables.)