The purpose of this study was to analyze the weatherproof for insulation, warpage and unification characteristics of extrusion cement panel(ECP) according to the variation of external environment. Result to analyze mechanical properties of ECP in a preparatory experiment decided 50% about replacement ratio of insulation materials for fine aggregate as optimum mix of ECP. The weatherproof of ECP using 50% insulation materials were as follows; In insulation characteristics, the thermal conductivity after freezing and thawing test was higher than that after change of temperature and humidity. In warpage characteristics, bending strength and deflection were examined. V and PL with low density had low bending strength after freezing and thawing. The deflection of PL in bowing test was higher than another because hollow bead as insulation materials. Finally, unification characteristics of ECP followed from high quality as low length variations and good bond strength.