This research aimed at studying the relationship between the perceived teacher autonomy support, basic psychological needs (autonomy, competence and communication), intrinsic motivation and effort in Structural equation modeling method. 287 freshmen of Babol’s boys high schools were selected through stage cluster sampling method. These subjects answered to the Learning Climate Questionnaire (Black & Deci, 2000), Basic Need Psychological Scale (La Guardia et al. 2000), Intrinsic Motivation Scale (1989) and Effort Scale (Dupeyrat & Marine, 2005).Results of the study revealed that teacher autonomy support exerted a direct and significant influence upon the psychological needs satisfaction, and this would have an indirect influence upon the students’ intrinsic motivation. In addition, autonomy and competence had a positive and direct influence upon the intrinsic motivation, while the effect of communication on the intrinsic motivation was not significant. Intrinsic motivation exerted a direct and significant influence upon students’ effort. In general based on the results of the study it can be concluded that teacher autonomy support can meet the students’ basic psychological needs which can in turn influence their intrinsic motivation

Keywords: autonomy, basic psychological needs, Intrinsic motivation, effort