Despite the nationwide anti-smoking efforts, cigarette smoking has increased among adolescents across ethnicity/culture in the last decade. Although numerous studies and tobacco control programs have focused on many specific aspects of cigarette smoking among adolescents, the process by which adolescents program from never smokers to susceptible non-smokers, smoking experimenters, and regular smokers has not been sufficiently investigated. The dramatic ethnic and cultural differences in cigarette smoking among adolescents suggests the importance of acculturation, media and social influences in smoking acquisition. With longitudinal data from two cohorts, 17,500 7th graders, 12,500 from California, a state with the most ethnically diverse population in the United States, and 5,000 from Wuhan, China, a mid-level industrial provincial capital with 7 million Han population, this project seeks to understand the progression process of cigarette smoking among adolescents across culture and ethnicity. With a cross-culture and transdisciplinary approach, the progression from never smokers to susceptible non-smokers, to smoking experimentation and, finally to regular smokers including addicted and chipper smokers will be examined. In addition to pro-tobacco media, social influences (parents and peers), the role of acculturation in predicting smoking progression will be examined in detail. Cross-ethnicity, cross-country and cross- gender comparisons will also be made to gain inside into gender and ethnic differences in cigarette smoking progressions. The findings from this project will facilitate the development of effective anti-smoking interventions geared toward our increasingly multi-cultural society.