To investigate the effects of pressure and temperature on lipoxygenase (LOX) in meat, changes in LOX activities in minced pork and in crude enzyme extracts under different conditions of pressure (131.82-468.18 MPa), temperature (23.18-56.82 o C), and duration (6.59-23.41 min) were evaluated using response surface methodology. LOX activities in extracts exhibited a decrease with an increasing treatment temperature, pressure, or duration. Each of these factors alone had a significant (p<0.05) effect on LOX activities. Activation of LOX in most minced pork treated at less than 400 MPa was observed. Treatment pressure and temperature, and interactions between pressure and temperature and between duration and pressure, significantly (p<0.05) affected LOX activities. LOX showed higher stability in muscles than in extracts during combined pressure-heat treatments. The most important factor affecting LOX was treatment temperature for extracts and treatment pressure for muscles.