To provide a solution for addressing the difference between the existing last freezing indexes and the real performance of Fuji apple flowers in Shaanxi province,this research mainly used an artificial climate box to evaluate the indexes. The result showed that the critical frost temperature was-2℃. Meanwhile,the colder the temperature went and the longer it lasted,the more damaging rates the apple flowers encountered. Abrupt fluctuations in temperatures could easily result in sever damages on apple flowers. The level that the flowers became frozen was related with the openings of the flowers. The more the flowers opened,the more severe they suffered. However,no significant correlations were discovered between the damages and the locations of the flowers-central or peripheral. On the basis of these observations, this research established a new last freezing index,which included level of freeze,extreme minimal temperature, duration for temperature below 0 oC,freezing rate and freezing performance. In addition,the real agreement and the basic agreement rates of the indexes were greater than 70%,indicating that the indexes could be used in practice.