Abstract: Irrigation management reform is useful to improve the management efficiency of water resource and irrigation management system; it is also able to reduce the households′ livelihood vulnerability. Learn from Sharp′s quantitative research on livelihood assets in Africa and Yu Gull’s livelihood vulnerability assessment on the farmers and herdsmen，reference to IPCC’s center interpretation on vulnerability，namely，Vulnerability=Risk-Adaptation，risk is measured by the degree of damage，adaptation is measured by the farmers' levels of existing capital and adaptation strategies，in order to eliminate overlap and duplication between the indicators and targets set by the phenomenon of subjective and arbitrary，we use expert evaluation method to determine the weight of each index. Taking Inner Mongolia for example，the paper makes a quantitative assessment of livelihood vulnerability between farmers in irrigation management reform area and non-farmers. Based on 353 peasant households′ survey data of 5 counties in Inner Mongolia，the paper evaluates the livelihood vulnerability of households from irrigation reform areas and non-reform areas. The study found that the household’s extent of the damage is 1.05 in irrigation and 1.33 in non-reform areas，the household’s livelihood capital value is 1.71 in irrigation and 1.64 in non-reform areas，the household’s adaptation strategies measurement is 1.53 in irrigation and 1.45 in non-reform areas. We can calculate the vulnerability value from the above results，the households′ vulnerability is -2.19 in irrigation and -1.76 in non-reform areas，the households both have higher adaptive capacity in two regions，but households′ vulnerability in non-reform regions is greater than in the reform regions. The irrigation management reform is significant to reduce the vulnerability of households ' livelihood. The reason is that the reform has improved the fragility of the environment，enhanced the level of livelihood capital and households′ the adaptive ability. To improve the households' benefit levels and reduce the livelihood vulnerability，in later work，we need to strengthen the capacity-building for sustainable livelihoods of households，and need government′ s right guidance and strong support，but also to strengthen the households' risk capacity to resist natural disasters，in order to reduce the households′ livelihood vulnerability by multiple channels. This paper develops a livelihood vulnerability assessment index system on the basis of sustainable livelihood framework，and then makes a comparative analysis of livelihood vulnerability between reform farmers and non-farmers; those studies belong to certain degree of innovation. Many domestic and foreign scholars have studied the problem of irrigation management reform from different aspects，but very few people analyze the impacts on farmers' livelihood vulnerability of irrigation management reform from the perspective of sustainable livelihoods. Especially for China，the irrigation management reforms have implemented for many years in our country，only rare studies involved on household livelihoods，and the studies which combined the irrigation management reform with the household livelihoods vulnerability have not yet seen. Adopting which indicators to measure irrigation management reform in respect of farmers' livelihood vulnerability is the question we should answer. This study makes up the deficiency in this respect，and hopes to have certain significance on research in this area.

Key words: Inner Mongolia, irrigation management, livelihood, vulnerability, adaptation tactics