Since microwave method has higher power densities, so microwave method can increase reaction rate and reduce time reaction and save electricity power. In this research, calcium silicate was synthesized by sodium silicate from rice husk and calcium oxide from egg shell by using microwave method by heating at 700 W for 1, 3, 5 minutes and calcined at 800 and 1000 ᵒC for 2 hr. Calcium silicate was characterized by Fourier transform infrared spectroscopy, scanning electron microscopy and X-ray diffractrometry