Objective: To examine the changing trajectories of sleep problems and teacher support among first year middle school students and their covariant relationship,so as to provide theoretical basis for the prevention strategy of sleep problems for the first year junior high school students. Methods: In September 2020, a multistage cluster random sampling method was used to select 1 027 first year junior high school students from two schools of Anshun and Guiyang cities in Guizhou Province for survey and follow up assessments (T1:September 2020, T2:October 2020, T3:November 2020, T4:December 2020). The Student Perceived Teacher Support Behavior Questionnaire and Pittsburgh Sleep Quality Index Scale were administered to assess sleep problems and teacher support among first year junior high school students. Spearman correlation analysis was used to examine the relationship between sleep problems and teacher support. A multivariate latent growth curve model was employed to analyze the changing trajectories and covariant relationship between teacher support and sleep problems, followed by a multi group analysis. Results: For first year junior high school students, teacher support scores at T1-T4 were 4.00 (3.47, 4.53), 4.00 (3.47, 4.58), 3.95 (3.47, 4.61) and 4.00 (3.48, 4.67), respectively; sleep problem scores were 0.83 (0.50, 1.17), 0.67 (0.50, 1.17), 0.83 (0.50, 1.17) and 0.67 (0.33, 1.17), respectively. Spearman correlation analysis revealed that teacher support and sleep problems were negatively correlated across all four period ( r =-0.28 to -0.14, all P <0.01). Teacher support perceived by students showed a linear increasing trend (intercept=3.98, slope=0.02), while sleep problems showed a linear decreasing trend (intercept=0.86, slope= -0.02 ) (all P <0.05). The multivariate latent growth model indicated that the rate of increase in teacher support after enrollment effectively predicted the rate of decrease in sleep problem levels ( β=-0.34, P <0.01). Multigroup analysis showed that the covariant relationship was not moderated by gender or boarding status (both P >0.05). Conclusions The increase in teacher support experienced by first year junior high school students during the transition period after enrollment, accompanied by a reduction in sleep problems, constitutes a dynamic protective process. The process is not moderated by gender or boarding status.