A numerical simulation was performed to analyze the flow and heat transfer associated with growth of a single bubble in the reduced-gravity condition. No assumption was made on the shape of bubble during its growth. Numerical calculations demonstrated that the time history of the bubble shape in the reduced - gravity differs from that in the terrestrial condition, and the flow and heat transfer fields also change as the buoyancy convection is weakened as the gravity is reduced. To evaluate the potential thermocapillary effect on bubble dynamics, the temperature distribution was artificially imposed on the bubble cap surface although such situation is not expected in the bubble growth of pure fluids. Calculated results under such a hypothetical situation show that the thermocapillary convection is negligibly small even if it might exist in the reduced-gravity condition.