The effect of high-pressure (HP) treatment at 100-300 MPa on pectin methyl esterase (PME) activity was studied.A PME purified from orange peel was pressure stable, at 25℃ no loss of activity was noticed with increasing applied pressure (100-300 MPa) and time (5-25 min) in phosphate buffer at pH 7.5.The highest activity was 134% after 25 min at 200 MPa.A commercial PME in food industry was also pressure stable by pressure (100-300 MPa) and time (5-25 min) at pH 4.0.The highest activity was 145% after 15 min at 300 MPa.