Solubilities of silicon and oxygen in liquid iron coexisting with Mg-perovskite were investigated at 27 GPa and 2320-3040 K to discub a core formation proceb and light elements in earth's core. The earth's core contains light elements and these light elements were dibolved into liquid iron to form the core during core formation proceb. A reaction between the liquid iron and Mg-perovskite must have occurred at a base of a deep magma ocean and could have provided silicon and oxygen as the light elements into the liquid iron. In this study, high prebure and temperature experiments were conducted with a Kawai-Type multi-Anvil apparatus. The liquid iron reacted with Mg-perovskie to form the magnesiowustite and silicon and oxygen dibolved into the liquid iron at temperatures above 2640 K. The solubility of silicon in the liquid iron decreases, whereas that of oxygen increases with increasing oxygen fugacity, and both increase with increasing temperature. This implies a pobibility that silicon and oxygen are the light elements in the earth's core.