The in vitro antioxidant activities of five melania snails in the genus Semisulcospira (S. coreana, S. forticosta, S. libertina, S. tegulata and S. gottschei) were tested in detail. The total phenolic contents of the snails ranged from $32.3{pm}1.0$ to $87.9{pm}6.9$ mg gallic acid equivalent (GAE)/g dry sample. The $EC_{50}$ values for the 2,2-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activities were $2.245{pm}0.179$ mg/mL for S. coreana and $9.319{pm}1.276$ mg/mL for S. gottschei and differed significantly (P<0.05) among the tested species. The superoxide dismutase (SOD)-like activity was highest for S. gottschei at 67.2% and lowest for S. forticosta at 4.7%. However, no significant differences among the species were recognized for the peroxynitrite anion scavenging activity. Comparing the correlation coefficients between the total phenolic contents and the DPPH radical and peroxynitrite anion scavenging activities, there was a low level relationship between each activity.