Abstract: As the important force to promote the development and progress of agricultural production, the agricultural extension is an extremely large social system engineering, which goes through the entire history of agricultural development. The agricultural extension in China has sprouted since the emergence of agricultural activities, whose history can be dated back to the ancient times. And with the establishment of agricultural extension procedures, it has gradually become regular. By studying the history of agricultural extension in the ancient China, it is found that the agricultural extension in the ancient China has contributed to promoting the agricultural development, and the ideas included in it, such as the innovative spirit, the agriculture priority idea, the idea of cooperation between officials and ordinary people, and the idea of integrating theory with practice still have precious value at the present times.