Oxygen is essential for energy production in living organisms. Therefore, it is important to measure vital oxygen partial pressure for medical diagnosis and clinical practice. In this study, we suggested the flexible oxygen sensor which can paste on to curved surface organs or tissue and directly measure the oxygen partial pressure of the pasted region. To sustain such sensor we applied phosphorescence lifetime measurement into flexible optical system. This paper proposed the calibration of oxygen senor using flexibility applicable light source devices under different oxygen concentrations.