Abstract: Hami melon ‘Early Queen’ was used to study the Effect of BTH(benzothiadiazole), Amistar, KDF(kang du feng) treatment on quality, yield and resistance to leaf and fruit disease of hami melon , used a randomised complete block design, during growth period. The soluble solid content(SSC), firmness, single fruit weight, and yield of melon, and resistance to fruit and leaf disease of melon were investigated. The results indicated that all three treatments can increase SSC, single fruit weight, yield of melon fruit. Index of fruit shape was decreased by BTH treatment, increased by KDF treatment at harvest. Fruit colour and cracking was improved due to treatments during development of melon. Indexes of fruit disease treated with Amistar, BTH and KDF were declined at 14.9% and 12.4% respectively. Index of bacterial spot of leaf treated BTH compared with CK was reduced at 0.95. Quality and yield of melon was not affected by BTH treatment. Disease of fruit and leaf of powdery mildew and bacterial spot were suppressed by BTH treatment during development stages of melon.