Several series of trawl survey was carried out in the coastal waters of southeastern South China Sea using commercial trawler. Six species of ponyfishes were caught throughout the study. Adult fish species were examined for their systematic differences. Based on systematic differences, a pictorial description of each species was built up. Detail population growth of dominant species was estimated using the allometric regression analysis of length (L)-weight (W) relationship (W= aLb). The results showed that the regression coefficient b was 3.337±0.105 for Photoplagios stercorarius, 2.530±0.298 for Photopectoralis bindus, 2.690±0.330 for Secutor insidiator and 2.211±0.507 for Gazza minuta respectively. Stomach contents analyses revealed feeding guilds of each species of fishes. Mean trophic level for P. bindus was 3.222±0.491, G. minuta was 2.753±0.291, P. stercorarius was 2.662±0.316, S. insidiator was 2.865±0.298, Leiognathus jonesi was 2.490±0.267 and Leiognathus oblongus was 2.413±0.296 respectively. The mean value of RLG for P. stercorarius was 0.8740±0.0576, G. minuta was 0.5135±0.0942 and P. bindus was 1.1399±0.2611. Reproductive biology of the selected species of ponyfishes showed that the gonads were mono-lobed with maturing and matured oocytes stages at time of sampling. A mean value of GSI for P. bindus was 4.002±0.650, P. stercorarius was 2.540±0.430, S. insidiator was 5.638±1.114, Gazza minuta was 0.382±0.070, L. oblongus was 2.925±0.820, L. jonesi was 1.578±0.821 and Nuchequula decora was 2.569±1.451 respectively.