Objective: This study examined the interrelations between Chinese and Canadian identity development during adolescence over an 18-month period using an individual-in-context perspective. We simultaneously considered the roles of youths' cultural behavior practices and their gender for predicting identity processes. We also examined whether practicing heritage cultural behaviors interferes with or is unrelated to national identity development and vice versa. Method: Adolescents with Chinese backgrounds (N = 152, 52% female; Mage = 14.95 years at Wave 1; SD = 1.70) were recruited from either a large metropolitan or midsized city in Canada. All parents were foreign-born, as were 80.2% of the adolescents. Results: Confirmatory factor analyses suggested that males and females reported a mostly stable sense of cultural identity and similar patterns of interrelation among identity belonging and exploration. There were two exceptions: Males did not report stability in Chinese identity belonging, and higher Canadian identity predicted increases in Chinese identity for males but decreases in Chinese identity for females. For both genders, more engagement in cultural behaviors predicted identity development within each cultural dimension and there were no associations across cultures. Conclusion: The data suggest that identity development in adolescence is fairly stable for Chinese Canadians. The evidence of gender differences in the interrelations of identity components underscores the value of considering multiple social identities. Finally, the finding that cultural behaviors support identity development within a culture and does not interfere with between-culture identity development suggests that providing opportunities to engage in heritage and national cultural behaviors can foster bicultural identity development. (PsycInfo Database Record (c) 2022 APA, all rights reserved).