Abstract: A sand culture experiment with 4 potassium concentration levels(0,1. 5, 3. 0and 15 mmol/L) was conducted. When the maize growing in 5 leaves, the pots were putinto growth chambers with two different temperatures(8℃ and 25℃ ) for 4 days tostudy the effect of potassium on the chilling resistanee of maize plants. The resultsindicated that application of potash fertlllzer. the potassium content of maize shoots wasincreased. After 4 days low temperature treatment, some leaves of maize began to wiltand the wilt rate of maize leaves was decreased from 73. 7% with 0 mmol/L K level to4. 5% with 15 mmol/L K level, while maize was normal growth at 25℃. The results alsoindicated that potash fertilizer decreased the activity of peroxidase and memberaneinjury of maize leaves induced by chilling stress. Therefore, appropriate application ofpotash fertilizer might improve chilling resistance of maize seedlings.