The biological activities of water extracts from different fruit parts, such as peel, flesh, and placenta, of oriental melon were investigated. The concentrations of total phenolic in fruit extracts were $816.37;{mu}g/ml$, $385.23;{mu}g/ml$, and $925.56;{mu}g/ml$, respectively. Whereas the total flavonoid content in the peel extracts was $231.21;{mu}g/ml$, those in the extract of flesh and placenta were $8.16;{mu}g/ml$ and $36.07;{mu}g/ml$, respectively. The DPPH free radical scavenging activity of each fruit extract at 10,000 ppm was 34.84% for peel, 10.70% for placenta and 9.26% flesh. The ABTS radical cation decolorizing activity of each fruit extract at 10,000 ppm was in fruit extracts were 72.92% for peel, 48.0% for flesh and 74.31% for placenta. In addition, xanthine oxidase inhibitory activity, ${alpha}-Glucosidase$ inhibition activity, and tyrosinase inhibition activity of the peel extracts appeared to be higher than those of placenta and flesh. Taken together, these results indicated that the peel part of oriental melon contained higher level of total flavonoid content, and several physiological activities including antioxidation, ${alpha}-Glucosidase$ inhibition activity, and tyrosinase inhibition activity than did the flesh and placenta parts, and suggested that the peel might have a potential to be applicable as a source for functional foods.