Previously, we have reported expressed sequence tags (ESTs) analysis on the land snail, Nesiohelix samarangae (Ns). Of these ESTs, we have identified four partial fragments of N. samarangae cytochrome oxydase I (NsCO-I) gene which lead to obtain an 852 bp partial cDNA. Since NsCO-I is one of the best-known molecular phylogenetic markers, we have attempted to conduct comparative in silico analysis by using the NsCO-I gene. The combined results from BLAST analyses, multiple sequence alignment and molecular phylogenetic study of NsCO-I cDNA indicate that N. samarangae has similarity to three land snails such as Elona quimperiana, Euhadra herklotsi and Euhadra idzumonis.