Abstract: The paper gives the definition of agricultural engineering technology extension, which is the planned activities for transferring the advanced experience, advanced technolgy and advanced management and administration technique in the field of agricultural engineering to peasants in improving their agricultural productions, daily lives and rural industries through suitable ways and means. In philosophic speaking, it is the way to transfer the potential productive forces into the real productive forces in the field of agricurtual engineering.The paper states the significance of agricultural engineering technology extension with historical facts both in China and other foregn countries.The paper introduces the six approaches to rural extension by Mr. Bertus Haverkort from the ICRE, 1983. The paper also summarizes the agricultural engineering technology extension in China since 1949, the Liberation of Chinese People, and the features of agricultural engineering technology extension. Here, the author wishes to point out the differences between the extension work of agricultural technology and agricultural engineering technology as follows: (1) The extension person not only teaches peasants the engineering techniques but also the agricultural techniques before, within and after producton in the agricultural engineering tecbnolgy extension. (2) when extending the machines, equipments or other engineering facilities,the extension man should teach peasants a complete set of technique such as how to install, run,repair, maintain, etc. (3) The extension man has to monitor the quality of those engineering products. (4) Sometimes, the extension man will help the manufacturers to get the raw materials or the manu facturiug techniques of the equipments to be extended. (5) If peasants have some contradictions with manufaeturer, the extension man should coordinate the contradiction.saThe paper asks the agricultural engineering extension men ought to have the same mind as peasants and the spirit of bearing hardship and standing hard work.