Background: This study translated the International Positive and Negative Affect Schedule Short Form (I-PANAS-SF) into Chinese and examined its factor structure and measurement invariance in Chinese adolescents in Hong Kong. Methods: A sample of 4136 Chinese adolescents in Hong Kong was invited to complete a set of questionnaires. The factor structure of the I-PANA-SF was examined using confirmatory factor analysis (CFA) and exploratory structural equational modeling (ESEM). Internal consistency reliability was evaluated using Cronbach's alpha coefficients, and nomological validity was assessed using bivariate correlations between positive affect (PA) and negative affect (NA) subscales with effort, worry and lack of concentration. Finally, measurement invariance across genders and grades was examined to evaluate the invariance of the I-PANAS-SF. Results: Factor structure analysis suggested that the ESEM model outperformed the CFA model. The results of ESEM analysis indicated that one item ("alert") was problematic and a 9-item two-factor measurement model with that item removed was a better fit for the data. The Cronbach's alpha values were above 0.70 (0.81 and 0.83), revealing excellent internal consistency reliability. The PA subscale was positively associated with effort and negatively associated with worry and lack of concentration. The NA subscale was negatively associated effort and positively associated with lack of concentration and worry, indicating nomological validity. Finally, measurement invariance analysis revealed strict invariance across genders and grades. Conclusions: The results of the study provide preliminary support for validity and reliability of the 9-item Chinese version of the I-PANAS-SF and suggest that it is suitable for use among Chinese adolescents in Hong Kong.