PROBLEM TO BE SOLVED: To provide a method to strengthen cold resistance in a boot stage of a gramineous plant.SOLUTION: A method to strengthen cold resistance in a boot stage of a gramineous plant includes application of: a cold resistance reinforcement in the boot stage of gramineous plant, the reinforcement containing at least one selected from salicylic acid, salicylic acid precursors, salicylic acid derivatives and those salts; and at least one selected from salicylic acid, salicylic acid precursors, salicylic acid derivatives and those salts.