Organic thin film transistors(OTFTs)are elemental units in light-weight,flexible and low-cost organic electronic devices,which are of great fundamental interests in materials science and are also recognized as a growing market for industry.Because OTFTs are interface devices with their performance highly dependent on the interface between organic semiconductors and gate dielectrics,control of interface structures and properties is as important as development of new semiconductor materials for the ultimate success of OTFTs.We have recently developed two types of novel self-assembled monolayers(SAMs)for OTFTs.One is SAMs of phosphonic acids as interface engineering strategies for solution-processed OTFTs with high field effect mobility,and the other is a SAM of non-planar organic semiconductors,which leads to monolayer field effect transistors.This talk will present our research on the above two aspects.