Objective To develop Chinese Infants Sleep Assessment Scales (ISAS) suitable for Chinese infants under the age of 1 year old, and to evaluate the reliability, validity and feasibility of the scales. Methods The scale was divided into two ages, 0—3 months and 4—11 months, according to the infants' sleep development characteristics.Firstly, an item pool with 4 dimensions of sleep rhythm, bedtime arrangement, night wakings and sleep disordered breathing was constructed.Then, the scales were compiled and evaluated through preliminary screening, modification, item analysis, validity analysis, reliability analysis and confirmatory factor analysis. Results The ISAS (0—3 months) and ISAS (4-11 months) both had 14 items, including 4 factors of sleep rhythm, bedtime arrangement, night wakings and sleep disordered breathing with total variance explained of 56.61% and 55.02%, respectively.The items of the two scales were slightly different.The item-level content validity of all items in both scales ranged from 0.83 to 1.00.The two scales were positively correlated with Brief Infant Sleep Questionnaires (BISQ) in terms of sleep latency, number of night wakings and sleep duration, with correlation coefficients of 0.31,0.41,0.39 and 0.32,0.66 and 0.38, respectively.There were statistically significant differences between community sample and clinical sample in the total scores of the two scales and most of the factors (except the sleep disordered breathing factors of the 0-3 months) (P<0.05).The Cronbach's α coefficients of the two scales were 0.681 and 0.673, and the test-retest reliability were 0.75 and 0.74. Conclusion The two scales have relatively stable factor structures and good reliability and validity, which can be used for early screening of infants' sleep problems.