This study examines the relationship pattern of the motivational climate,satisfaction of the psychological needs and self-determined motivation in youth male athletes based on the self-determination theory (Deci & Ryan, 1985, 2000). A sample of 255 athletes ranging from 12-14 years of age from varity of team sports completed the Motivational climate in youth sport, behavioral regulations toward sport, and the basic needs in sport scale. Pearson correlation, Confirmed factor analysis, Structural Equation Modeling analyses were used to examine the research hypotheses. The results revealed mastery oriented climate have a direct, positive influence on relatedness, competence, and autonomy.Competence and relatedness influenced self-determination, positively. Relatedness, competence, and autonomy had mediatory role in affecting mastery climate on self-determination. The results indicated that mastery motivational climate is an important motivational variable in youth male athletes which can influence self-determination by affectingpsychological needs.