Rhizopus soft rot caused by Rhizopus stolonifer occurred on melon (Cucumis melo L.) in the box at Jinju City Wholesale Market of Agricultural Products at Gyeongnam province in Korea. The infected fruits were rapidly water-soaked, softened, black and eventually rotted. The symptoms were infected from wounds at harvest time. The colony were white to light brown, formed much sporangiospores. The optimum temperature of the fungus was 30 oC. Sporangia were globose or hemispheric, white at first and gradually to black, and 80~195 µm in size. Sporangiophores were 12~24 µm in width. Columella were hemispheric, and 70~90 µm in size. Sporangiospores were irregular round or oval, brownish-black and 9~20 × 6~8 µm in size. On the basis of symptom, mycological characteristics and pathogenicity to melon, the causal fungus was identified as Rhizopus stolonifer (Ehrenb.) Vuill.. This is the first report of Rhizopus soft rot by R. stolonifer on melon in Korea.