In this study,carbohydrate content changes of muskmelon plants under hypoxic stress were investigated on two varieties which had contrasting hypoxic resistant traits to explore the relationship between plant carbohydrate content and its hypoxic tolerance.The results showed that under hypoxia stress,muskmelon root starch content decreased,while starch accumulated in stems and leaves.In hypoxia-resistant cultivar ‘Dongfang xingguang’,the degree of starch accumulation in leaves was significantly higher than that in the susceptible one.Total soluble sugar,sucrose and fructose contents all increased during hypoxia stress in muskmelon plants,especially in stems and leaves,and the degree of increment was significantly higher in the resistant cultivar ‘Dongfang xingguang’ than the susceptible one.The glucose content in roots continually decreased after hypoxia treatment,while in stems and leaves,it initially increased and then decreased to a level lower than that of control after 8 days hypoxia treatment.The results indicated that carbohydrate content and plant hypoxia-resistance were closely correlated;hypoxia-resistant varieties had higher contents of soluble sugar,sucrose and fructose than susceptible ones under hypoxic stress,and higher contents of soluble sugar,sucrose and fructose in planta were plant’s adaptive responses to hypoxic stress in muskmelon.