The thermal expansion valve is used many vapor compression refrigeration systems such as refrigerator, air- conditioner etc. Hence many techniques have been investigated on thermal expansion valve to increase COP of VCR system. COP of thermal expansion valve can be increased either by controlling the bulb pressure or by decreasing compression work. This is an attempt to design expansion valve for increased COP with respect to mass flow control of refrigerant and the particular thermal parameter which are affecting to COP. The validation of design of thermal expansion valve is planned to validate by CFD analysis.