Abstract: Based on grey system theory, the study conducted the gray system analysis on main indexes of 14 introduction alfalfa cultivars in dryhot valley region of Jinsha River, including fresh yield, dry yield, plant height, tiller number, stemleaf ratio and crude protein content. The order of weight of main production indexes in the synthetic evaluation model was that crude protein contentfresh yieldstemleaf ratioplant heightdry yieldtiller number. A comprehensive alfalfa cultivar evaluation model was established according to the weight of main indexes, and comprehensively evaluated the production performance of alfalfa cultivars with model, the results showed that the cultivar Hunterriver（7455）earned the maximum evaluation value, and it had relatively outstanding comprehensive productivity performance, which indicated that it was suitable for both spreading and planting in special ecological condition of dryhot valley region of Jinsha River.