Abstract: Alkoxyl phosphate was synthesized. The extreme pressure, anti wear properties and thermal stability of the synthesized alkoxyl phosphate as additive in liquid paraffin were investigated and compared with SO on four ball machine and Perkin Elmer thermal analyzer. The results indicate that alkoxyl phosphate is effective in improving the anti wear properties and load carrying capacity of liquid paraffin and has higher thermal stability than SO. The gear oil formulated with alkoxyl phosphate as the main component shows better extreme pressure and antiwear properties as compared with the currently available gear oils at home and abroad.