Abstract:species, belonging to the family Nemipteridae, order Perciformes, are widely distributed in the tropical and subtropical waters of the Indo-Western Pacific. Morphologically, a number of closely related species share similar external coloration and patterns, resulting in difficulty identifying and classifying them based on morphological evidence alone. Despite this, priorevaluation of has primarily relied on morphological data, with few molecular phylogenetic data currently available for this genus. We analyzed the molecular phylogenetic relationship among seven common species collected from the Indo-Western Pacific. Partial sequences of the 1st intron of the S7 ribosomal protein gene were obtained for seven species. We used sequence data from sequences ranging from 734 bp to 746 bp and homologous sequences of 743 bp were obtained for phylogenetic analysis after alignment. Of the 743 bp aligned sequences, 386 sites were conservative, 351 sites were variable, and 289 were parsimony-informative. The content of A+T (54.1%)was lower than that of G+C (45.9%). The genetic distance among the seven , calculated using a Kimura two-arameter model, were between 0.042 and 0.294. We observed a number of insertions and deletions in the S7 ribosomal protein gene sequences. The insertions and deletions at 167 bp, 182 bp, 474 bp, 608 bp, 662 bp within , and at 227 bp, 332 bp, 401 bp, and 604 bp within were identical. We constructed molecular phylogenetic trees using the maximum likelihood and Bayesian inference methods. The seven N. japonicus and N. bipunctatus and were clustered in a separate clade. These phylogenetic relationships were consistent with their morphological classifications. However, the phylogenetic position of Nemipterus species were divided into two morphologically distinct groups according to the length of upper and lower caudal fin lobes. The two lobes are of equal length in have an elongated trailing filament from their upper caudal fin and the upper fin lobe is longer than the lower. Our results suggest acombination of more morphological and molecular evidence is needed for further phylogenetic studies of the genus.