[Objective] The study aimed to explore the influence and mechanism of salicylic acid(SA) on cold resistance of wheat seedling.[Method] With a wheat variety Zhengmai 9023 as tested material,0.1 mmol/L SA was sprayed on wheat leaves with water as CK.When the first leaf of wheat was open,each half seedlings of each group was cultured under normal temperature(20 ℃) and low temperature(4 ℃) resp.After 5 days,the physical indexes of cold resistance were measured on wheat seedlings.[Result] The activity of SOD enz...