Abstract: Based on the recognization of that the essence of the "backward" is the unrational structure which is the cause of unfully utilization the available resources,the authors pointed out in this paper that development is the changing processes of structure and function,overcoming and alternating limited factors.Agriculture can be generalized as the body of four processes;ecology,product,yield,technical and economy.The different combination of those four processecs forms different kinds of agriculture which can be divided into three developing stages:preliminary,developing and developed.At different stages there are different structures,functions,producing function,development goals and limited factors.The joining of those stages constitutes the processes of agricultural modernization.So when focus on agricultural development in a country the eco-economy type and developing stage should be identified.then goals of development can be correctly choiced and structures can be effectively adjusted.