This study examined sociodemographic patterns of parental expectations for academic performance, terminal degree, and future occupation for middle school students in China, and how these expectations influence students' screen-based and academic-related sedentary behaviors through parenting control practices.Based on data collected in 2013-2014 from 19,487 Chinese middle school students, bivariate logistic regressions tested associations between sociodemographic variables and parental expectations; structural equation models tested associations between parental expectations and students' self-reported daily time on TV/Internet/homework, with parental controls as potential mediators. Analyses were performed in October 2015.Chinese students spent 0.96 (SD=1.44) hours/day on TV, 0.56 (SD=1.20) on Internet use, and 2.79 (SD=2.07) on homework. Girls spent more hours/day on homework (2.98 [SD=2.07] vs 2.62 [SD=2.04]) than boys but less on TV (0.90 [SD=1.37] vs 1.02 [SD=1.50]) and Internet (0.42 [SD=0.98] vs 0.69 [SD=1.36]). More than 30% of students were expected by parents to reach the top five of their class, almost 90% were expected to earn a college degree or higher, and >80% were expected to have a professional occupation. Students in rural areas, with siblings, and with lower parental SES tended to bear lower parental expectations. Children experiencing higher parental expectations spent more time on homework but less time on TV/Internet, partially explained by stricter parental homework and screen control.High parental expectations suppress screen use but promote academic-related sedentary behaviors for Chinese children. Interventions should attend to academic-related sedentary behaviors and call for broader policies addressing sociocultural factors fueling high parental expectations.