It is difficult for previous theories to analyze the factors which influence regional economic growth and regional disparities, because the problems of factors in end and structural conformity of factors cannot be resolved by them. Supported by the logic of harmonious sustainable development, grads theory was expanded by generalized-grader-step to natural factors, economy, society, human resource, ecological environment and institution. The generalized-grads theory revealed the coupling relationship between grades distributions and crossed interaction mechanism in muti factors, conformed the main regional development theories and made the innovation on grads theory, and tried to resolve the problems of factors in end and structural conformity of factors.