Abstract: Making use of MOX fuel which is made up of different compositions, a calculation was made for supercritical water cooled reactor (SCWR). Taking account of fuel burnup, power distribution factor, temperature reactivity coefficient, a analysis was made for using UO₂ fuel and MOX fuel in SCWR and using different MOX fuels in SCWR. The results indicate that MOX fuel has a simple power distribution with UO₂ fuel, and has better fuel burnup, reactivity coefficient than UO₂ fuel in SCWR. MOX fuel may apply in SCWR with reasonable design, and has a better property.