Bagasse ash is one of the agricultural wastes and valuable biomass by-products in sugar milling. It was treated hydrothermally with hydrochloric aqueous solution at 100 °C and burned at 600°C for 2 hours under oxygen feeding. The obtained white ash was further used as natural silica source instead of silica sol because of highly silica content from an abundant supply of sugar industries in Thailand. Aluminosilicate precursor gel was prepared from alumina source and silica source via sodium silicate preparation. Different crystallization time was studied for the molar ratio of SiO2/Al2O3 = 2 at 100°C crystallization temperature. The phillipsite zeolite synthesized was characterized using various techniques; X-ray diffraction, Scanning electron microscopy, Fourier Transform Infrared Spectroscopy, and BET-N2 adsorption method. The results can be used as value added for bagasse ash utilization, minimize the environmental impact of disposal problems and further application for heavy metal removal.