A flexible temperature sensor array and a scanning system are developed in this paper. A 16×16 temperature sensor array in a 25×20 mm2 area is fabricated on a flexible copper-PI substrate using MEMS fabrication technology. Platinum is employed as the temperature sensing material, which is often so called the resistance temperature detector (RTD). Copper patterns on both sides of the flexible substrate serve as the row and column interconnects for scanning circuitry. In each element of the temperature sensor array, the resistance of platinum, which is patterned by lift-off process, can be measured by the scanning system.