The flexible organic thin film transistor(OTFT) array to use as a switching device for an organic light emitting diode(OLED) was designed and fabricated in the nanocontact printing and low-temperature process. The gate, source, and drain electrode patterns of OTFT were fabricated by nanocontact printing process. And dielectric layer of parylene and organic active semiconductor layer of pentacene formed at room temperature or at a temperature lower than 40. The nanocontact printing process using SAM and PDMS stamp made it possible to fabricate OTFT arrays with channel lengths down to even submicron size, and reduced the fabrication process by 10 steps compared with photolithography. Since the process was done in room temperature, there was no pattern shrinkage, transformation, and bending problem appeared. Also, it was possible to improve electric field mobility, to decrease contact resistance, to increase close packing of molecules by SAM, and to reduce threshold voltage by using a parylene.