Mass transport in the soil is governed by water movement or flux due to diffusion mechanism and gravitational force. The diffusion is driven by spatial pressure difference where the water flows from low suction region to high suction region. The flow mechanism is applicable under unsaturated soil conditions. In gravitational flow, the water flow from high elevation to low elevation, vertically downward motion, and the rate of flow is depending on the soil water saturation level. In addition, under temperature gradient environment, the mass transport could be attributed by vapor transport by temperature gradient, which is in addition to the vapor transport under pressure suction gradient. Modeling water flow in soil is often limited to water flux mechanisms. This study aims to compare water vapor flux with water flux in the coastal soil in Terengganu, east coast of Peninsular Malaysia. The mechanisms of water vapor and water fluxes were quantified using mass transport equation. The results showed that water vapor flux was significant in value when compared to water flux under drier soil region. As the soil water content increases, the contribution of water vapor to the overall mass flux reduces and it becomes insignificant. Furthermore, soil that develops temperature gradient resulting in mass flux of water vapor in nearing dry soil has comparable mass transport as the liquid water flux by matric suction gradient, thus, it implies the inaccuracy of using Richard's equation utilization, management as well as conservation of coastal soil ecosystem.