Expanded polystyrene particles having a polyvinyl acetate resin-based functional skin layer, and a process thereof are provided. The particle includes an inner expanded polystyrene layer; and a functional skin layer. The inner expanded polystyrene layer is formed by heating and expanding an expandable polystyrene bead or pellet, and the functional skin layer is formed by coating the surface of the inner expanded polystyrene layer with a functional coating composition having 10 to 99 wt % of a vinyl acetate based polymer and 0.1 to 90 wt % of at least one functional additive.