The effect of aluminium silicate filler on the morphology of the microcellular ethylene-octene copolymer (Engage) has been studied from SEM photomicrographs with variation of blowing agent and silicate filler loading in comparison to the unfilled vulcanizates. The average cell size, maximum cell size and cell density varies with variation of blowing agent and filler loading. Physical properties like relative density, hardness, tensile strength, elongation at break, modulus, tear strength decreases with blowing agent concentration. However tensile strength, modulus (100%), tear energy and hardness varies linearly with the density of the filled vulcanizates. The elastic nature of closed cells reduces the hysteresis loss compared to solid compounds. Set properties improve with blowing agent concentration. It is observed that stress relaxation behavior is independent of blowing agent loading i,e., density of closed cell microcellular vulcanizates. Theoretically flaw sizes are found to be about 2.57 times larger than maximum cell sizes observed from SEM photomicrographs.