Abstract: Proceeded from the essential characters of engineering science and based on the features of agricultural engineering objects the author tries to discuss the characters and features of agricultural engineering science. The fundamental difference between the agricultural engineering and the traditional engineerings such as civil engineering, mechanical engineering, chemical engineering and electrical engineering is that the agricultural engineering produces and improves the engineering object which is a complex system containing live and lifeless bodies. Meanwhile, this body system is closely related with its surrounding environment. Therefore, agricultural engineer should pay great attention to study the relationship between the agricultural living beings and their environments, and the relationship between agricultural living beings, their environments, and different kinds of engineering facilities.In this paper, author does not agree and presents his own ideas about following two statements, they are: "The agricultural engineering is an engineering measure used for agriculture." and "The agricultural engineering science is a border science between the traditional engineering science and agricultural biological science."