We studied the effect of variable temperature treatment on flower bud differentiation of Crocus sativus in order to provide theoretical basis for early flower bud differentiation. The bulb of C. sativus was treated by threestage variable temperature treatment ［20 ℃25 ℃20 ℃ (T₁), 20 ℃30 ℃25 ℃ (T₂), 25 ℃35 ℃25 ℃ (T₃), 25 ℃30 ℃25 ℃ (CK₁) and 25 ℃25 ℃25 ℃ (CK₂)］. The differentiation of flower bud was observed by paraffin section technique. The contents of starch, soluble sugar, soluble protein, endogenous auxin IAA, gibberellic acid (GA) and activities of catalase (CAT), peroxidase (POD) and superoxide dismutase (SOD) were measured. The results show that: (1) the corm of C. sativus treated with T₁ started flower bud differentiation earlier than other groups, the length and growth of flower bud of C. sativus treated with T1 were better than other groups, and the first flowering time of C. sativus treated with T₁ was more than one week earlier than that of control group. (2) T₁ treatment could promote the accumulation of soluble sugar, soluble protein and other nutrients, and increase the activities of SOD, POD and CAT. In addition, T₁ treatment could effectively regulate the contents of endogenous IAA and GA. The results showed that the change of external temperature could also indirectly regulate the synthesis and transportation of nutrients, antioxidant enzymes and plant hormones in Crocus sativus bulbs, thus affecting the dormancy and flower bud differentiation of plants, and ultimately regulating the flower bud differentiation and flowering. The appropriate threestage variable temperature treatment (20 ℃25 ℃20 ℃) could effectively regulate the initiation and duration of flower bud differentiation of Crocus sativus.