Occupational gender segregation can be traced back to gender-typed occupational aspirations formed early in life. Analyzing nationally representative data from the 2010–2018 China Family Panel Studies (N = 2,410 adolescents aged 10–19), we examine the relationships between parents’ occupations, their gender-(a)typical occupational expectations, and adolescents’ gender-(a)typical occupational aspirations. Our research makes three distinctive contributions. First, we clarify how gender-role modeling works by distinguishing adolescents’ direct imitation of parents’ occupations from their indirect gender-role learning based on the gender orientation of parents’ occupations. Second, we propose and test a new theory of “gender boundary-setting” to understand how the opposite-sex parent’s gender- typed occupation can erect gender boundaries that reinforce their children’s gender-typed aspirations. Third, we examine the role of parents’ gender-(a)typical occupational expectations in shaping adolescents’ gendered aspirations and how such expectations relate to adolescents’ social learning based on parents’ occupations. We find that girls’ gendered occupational aspirations are shaped by direct occupational imitation, indirect gender-role learning, gender boundary-setting, and parents’ gendered expectations, whereas boys’ aspirations are only shaped by direct imitation. Parents’ expectations and adolescents’ social learning operate independently of each other. Our findings provide new insights into the supply-side mechanisms underpinning the intergenerational reproduction of occupational gender segregation.