Abstract: The construct of locus of control originally proposed by J.B. Rotter,was redefined as a"Cognitive-Knowledge System Model",based on the empirical and theoretical analysis of the construct, together with the author's recent findings on blaming, excuse-making, life event perception and mental health. It was proposed that the individual's locus of control expectancy, in general, was a generalized tendency of internal or external control. Meanwhile, it was also influenced by the individual, s cognition of the specific situation where he/she is. There was significant interactions among the generalized control tendency,the cognition of the situation, and the social-cultural background of the individual. This model was the theoretical summarization of the relative findings with Chinese subjects, and it also was important reference to personality, social and clinical psychological theory and research.

Key words: locus of control, cognitive-knowledge system model, social-cultural background