This is a part of a three year longitudinal study on the physical and psychological development of Chinese school pupils. The revised form of Nowichi-Strickland Locus of Control for Children was administered to students from 4th to 12th grade while its simplified form was given to the 1st, 2nd, and 3rd graders. The findings were: (1) The belief of internal control increased with age among Chinese school children. (2) The score of internal control belief had significantly positive correlation with self acceptance and emotional maturity, but it correlated negatively with neuroticism. (3) Parental child-rearing practices perceived by children were found to have significant influence on the belief of internal control of the latter; and as far as such influence was concerned, father-child relationships seemed to have equal importance as mother-child relationships.