Melting characteristics of a solid phase change material in a inclined rectangular heat storage enclosure heated from one side is investigated experimentally. According to the inclination angle of the enclosure, the natural convection pattern in s liquid phase shifts from three-dimensional flow to two-dimensional one. The interface morphology is found to be dependent on the angle of inclination and heating wall temperature. The time-wise variation of the melt fraction is obtained for various inclination angled. Correlation equations of natural convection in a liquid phase are presented in terms of Rayleigh number, inclination angle and Stefan number.