Abstract: A newly promoted life-span theory of development is introduced here. This control theory employed two basic concepts of primary and secondary controls. Primary control directs at changing the external world to fit the needs of the individual. Secondary control targets at internal processes in order to minimize losses in, maintain, and expand existing levels of primary control. The concepts and the dimensional models of the two control processes are described,the development of control through the life course is analyzed, and an evaluation of the control theory is conducted in this paper.

Key words: life-span development, control theory, primary control, secondary control.