Objective: To identify the latent profile characteristics and associated factors of family intergenerational transmission of proactive health behaviors in overweight and obesity junior high school students, so as to provide a reference for promoting active health in adolescents. Methods: From October to December 2024, a stratified cluster random sampling method was employed to select 4 932 junior high school students with overweight and obesity from 18 junior high schools of three cities representing the eastern (Yantai), central (Zibo), and western (Zaozhuang) regions of Shandong Province. Latent profile analysis was used to explore the heterogeneity of family intergenerational transmission among those students. Univariate analysis and multiple Logistic regression analysis were conducted to identify factors associated with different profiles and to examine the influence of profile membership on junior high school students proactive health levels. Results: The intergenerational transmission of health behaviors in junior high school students could be classified into 3 latent profiles:the moderate modeling dysfunctional group (5.88%, n =290), the low modeling advantage deficient group (41.79%, n =2 061), and the high modeling functional harmonious group ( 52.33 % n =2 581). Univariate analysis showed that gender, urban/rural area, region location, paternal/maternal education level, family economic status, and only child status were significantly associated with the classification of latent profiles of intergenerational transmission in families of overweight and obesity junior high school students ( χ 2=7.63-165.22, all P <0.05). Multiple Logistic regression analysis revealed that, using the moderate modeling dysfunctional group as the reference, male students ( OR =0.71) and those residing in coastal cities ( OR =0.74) were less likely to belong to the low modeling advantage deficient group (both P <0.05); students with moderate family economic status were more likely to belong to the low modeling advantage deficient group ( OR =1.72， P <0.05). Conversely, students living in urban areas ( OR =1.43), those with fathers ( OR =2.53) or mothers ( OR =2.48) having a college degree or above, and those with moderate ( OR =3.89) or good ( OR =2.42) family economic status were more likely to be classified into the high modeling functional harmonious group (all P < 0.05 ). Using the low modeling advantage deficient group as the reference, residing in coastal cities ( OR =1.26), living in urban residence ( OR =1.14), having parents (father or mother) with a college education or above ( OR =1.91, 2.33), moderate or good family economic status ( OR = 2.27 , 3.17), and being an only child ( OR =1.19) were associated with a higher probability of belonging to the high modeling functional harmonious group (all P < 0.05 ). There was a statistically significant difference in active health behaviors among students across different latent profiles of family intergenerational transmission ( F =494.79, P <0.01). Conclusions The heterogeneity of family intergenerational transmission is associated the level of proactive health behaviors among junior high school students. Therefore, precision interventions should be implemented based on different categories of family intergenerational transmission, so as to strengthen the efficacy of intergenerational transmission of health behaviors and promote proactive health among junior high school students.