‘Xizhoumi 25’ Hami melon as test materials,the total four treatments:melon soaked in 55℃ hot water for 3 min,melon coated by 2% of chitosan,melon treated by two combination (heat treatment+chitosan coating),melon not treated as CK,then the melons were inoculated Alternaria alternata.The changes of disease resistance and physiology and biochemistry of melon were mainly studied.The results showed that electrolyte permeability,the respiratory rate and ethylene production rate were inhibited obviously,and GHT,GLU,PLA and POD activities were increased significantly at the post-storage by three treatments comparing with CK,thus the addition of lesion diameter and lesion depth were decreased effectively during storage,the resistance of disease was enhanced,rot was prevented effectively.The combination treatment was the best.