Abstract: The contents of protein and total soluble carbohydrate were determined in rind, endodermis, pulp and seeds of seed melon. Polysaccharide was isolated from the sections and the radicals scavenging activities were evaluated. The experimental results showed that the contents of protein were 6.65% in dried rind, 1.22% in dried endodermis, 5.60% in dried pulp and 30.04% in dried seeds, the contents of soluble carbohydrate were 33.94mg/g in fresh rind, 29.77mg/g in fresh endodermis, 58.94mg/g in fresh pulp and 32.95mg/g in dried seeds, respectively. The extracts were isolated from fresh rind, endodermis and pulp by ethanol-precipitating, from dried seed by water -dissolving and ethanol -precipitating, the polysaccharide contents in the extracts were 33.29% from fresh rind, 28.05% from fresh endodermis, 93.39% from fresh pulp and 15.77% from dried seed. The polysaccharide contents in the different sections of the melon were 0.17% in fresh rind, 0.016% in fresh endodermis, 0.19% in fresh pulp and 1.59% in dried seed. The extracts showed certain antioxidant activities on the radicals of hydroxyl, superoxide and DPPH. The antioxidant activities of the extracts from rind, endodermis, pulp and seed on hydroxyl radical and the extract from endodermis on DPPH were better than vitamin C.