A mass-balance Ecopath model of coastal areas in the Mekong Delta has been constructed for a quantitative description of the trophic structure of the ecosystem. The model is used to estimate the important biological parameters and relationships among the different ecologically important groups. The model is based on the data collected from bottom trawling. There are 14 functional groups based on 58 species from coastal areas in the Mekong Delta survey such as shrimps, squids, crabs, mackerel, small pelagics, demersal fishes, benthic feeders, predator fishes and trash fish. The biomass value was estimated from catch production and bottom trawling surveys. Results show that the estimated total biomass of exploited resources was 3.99 ton.km-2. The values of Ecotrophic Efficiency (EE) in the model are high (>0.5) for most groups of high trophic level. The results showed that those groups exploited by small mesh size and small living organisms were being heavily preyed upon in the ecosystem.