Abstract: The characteristics of the discipline of agricultural engineering: The task of a.e. discipline is to develop agricultural engineering technologies on the basis of intrinsic attributes of agricultural productions and the integrity of agricultural system at different level. It lays particular stress on the investigation of relationships among agro-biological matters environment and engineering measures. Countries having different social-economic conditions and natural resources should adopt different developing strategy of a.e. discipline.Problems in mechanics on agricultural engineering science and technologies: varous problems concerning mechanics could be found in the course of designing and developing a.e. facilities and technologies, most of them are well defined, oweing to the objects of a.e. discipline study are principally of biological matters. These probrems with irragular shape, nonisotropic and restricted by life cyde still show the charateristic of having three states (gas, liquid, solid) together and etc.. Many modern theories and methods of computational mechanics have been used to analyse and solve problems in agricultural engineering, besides traditional engineering mechanics, there still remain many fileds to be opened up, e.g., the cutting of bilogical materials, the tractive and tillage soil mechanics, water and particles movement in SPAC system, air dynamics, heat and mass transfer in bio-environment controlling and processing agro-products, as well as by means of taking mechanic methods to analyse physiological phenomenon in order to improve and develop a.e. facilities and technogies, etc.Only when the a.e. science and technologies have become popular demand of farmers, agonomists, can the solid foundation of a.e. discipline be impregnable. To develop a.e. discipline needs multi-disciplinary cooperation.