This paper aims at discussing the concept and connotation and evaluating index system of agricultural water resource vulnerability in hilly area of southern China.First,based on the analysis of the research result of vulnerability in the field of resource and environmental science,a concept of vulnerability of agricultural water resource which represents the characteristic of agricultural water resource system in hilly area of southern China is formed.Then the connotation about the vulnerability of agricultural water resource is probed.It is believed that the vulnerability of agricultural water resource includes two aspects of water quality and quantity,which consist of natural vulnerability,artificial vulnerability and burdening vulnerability.Finally,an assessment index system which concludes 12 indexes is built to express the vulnerability of agricultural water resource in the aspect of water quantity in Hengyang Basin which represents the typical hilly area in southern China.And the vulnerability degrees of 7 counties in Hengyang Basin are calculated by fuzzy matter element analysis method,the results show that vulnerability of five counties out of the total is serious.It is found by validation that the assessment results are consistent with the practical situation,indicating that the index system and the assessment method are credible.