The low freezing point diesel antiwear agent was prepared by using naphthenic acid and 1,3 propanediol as raw materials, toluene as water carrying agent. The effects of molar ratio, reaction time and temperature on the esterification rate of the product have been studied. Moreover, the product was characterized by IR spectra. The result show that the esterification rate could reach as high as 96.1% uner the condition of the mole radio of acid and glycol was 2.1∶1 at 150 ℃ for 1 h. IR spectra confirmed the formation of target product. The prepared product showed quite high kinematic viscosity and particularly low freezing point. When 200 μg/g of the antiwear agent was added to the diesel, the antiwear property could be enhanced and the freezing point of diesel was lowered down efficiently.