A method of high precision printing for manufacturing organic thin film transistor, comprising the following steps of: forming a gate on a substrate; forming an insulator layer on the substrate; forming a conducting wire electrode film on the insulator layer; forming a organic interlayer; forming a organic semiconductor layer on the organic interlayer; forming a polymer layer for channel length on the organic semiconductor layer; forming a organic electrode film; and forming a protective layer. Moreover, a means for forming layers of above mentioned method is a high precision printing selected from the consisting of Inkject Printing, Screen Printing, Blade Coating, Roller Coating, Nanoimprinting, Micro Contact Printing, Flexographic printing, Table coating and Spin Coating, etc.