We propose an application of Stokes Parameter Method (SPM) for determining cell parameters of reflective twisted nematic (TN) liquid crystal (LC) cells oy measuring Stokes parameters of the LC cells. The relationship between the Stokes parameters of the reflection light of the reflective TN LC cells and cell properties such as the thickness and twist angle are given on Jones matrix representation. The cell properties of the reflective LC cell are discussed and compared with those of the transmissive LC cell. The cell thickness of the reflective TN LC cell can be measured, but the twist angle cannot be determined by this method.