We establish the unsafe state indicator system reflecting the unsafe state of arable land within the scope of the city. Using analytic hierarchy process and entropy method, we determine the weight of indicator; using linear weighted method, we conduct comprehensive evaluation of unsafe operation of arable land resource system in Chengdu City during the period 1999-2010. Through the unsafe state analysis, we draw the following conclusion: the share of arable land area in total land area, effective irrigation area, the area of low-yielding field, application rate of chemical fertilizer per unit area of arable land, and application rate of pesticide per unit area of arable land, are the key factors for easing the unsafe state in the short term. Finally we put forth the following recommendations: strengthening profound understanding of the seriousness of unsafe state of arable land; strengthening the basic arable land protection; continuing to tap the quality enhancement potential of arable land; consistently implementing the guideline and policy of "Combination of Use and Maintenance".