Hydrodynamics fields, transport-diffusion of suspended sediment in MeKong river mouth area are calculated by ECOMSED Modelling. This result can be of service to research interaction of water in MeKong river mouth area and upwelling in the South of Central sea of Viet Nam. As a results, suspended sediment transport changed according as different seasons and tides. In the rainy season, suspended sediment could diffused to costal area sea of Ninh Thuan province mainly with maximum concentration about 50 to 70 mg/l (in ebb tide phases). In the dry season, it's transport was in Southern over the cape of Ca Mau with concentration about 30 mg/l (in ebb tide phases). The model verification of sea level and currents shown it could be accepted.