pNitrophenol was synthesized from pnitrochlorobenzene and sodium hydroxide with phase transfer catalyst under normal atmosphere. The effect of the amount of sodium hydroxide and reaction time on yield of pnitrophenol was studied. The optimum parameters for preparing pnitrophenol were proposed. The optimal reaction conditions were A1 6% as catalyst, pnitrochlorobenzene sodium hydroside molar ratio 1∶3, the concentration sodium hydroxide solution 50%, nitrobenzen as solution reaction temperature 140 ℃, reacti...