Abstract: Waterborne polyurethane was successfully synthesized by trimethylol propane monooleate (TMPM), isophorone diisocyanate (IPDI), polypropylene glycol (PPG) and so on. TEM, DLLS, FTIR, TGA and surface tensiometer were applied to characterize both the morphology of the micelle and the structure and properties of the samples. Results show that waterborne polyurethane is successfully synthesized with long aliphatic chains which made it easier to form regulative micelles; and the particle size increase with the increasing of the weight of TMPM. However, when the mass fraction of TMPM is up to 7%, the emulsion becomes unstable. The surface tension decreases with the increasing of the amount of TMPM and the molar ratio of —NCO and —OH. By the increasing of the degree of crosslinking, the surface tension will experience a summit. Introduction of the TMPM could enhance the film′s thermostability.