Bubbles dispersed in liquid are easily separable by gravity-induced buoyancy on the earth. In microgravity environment, however, the other external forces should be utilized to separate bubbles in liquids because the gravitational force does not work. Centrifugal force is frequently applied as external force for separation of a small density difference mixture on the earth. The gas-liquid system has large density difference, the gas-liquid separation by centrifugal force is considered effective under low gravity conditions. In this study, two types of centrifugal gas-liquid separation systems were investigated under low gravity conditions.