Abstract: The inhibition of high pressure thermal sterilization treatment (350 MPa and 50℃ for 10 min) on Weissella viridescens and Leuconostoc mesenteroides of low temperature cooked ham were investigated in the study. The germicidal efficacy of high pressure thermal sterilization was evaluated by thin layer plate counting method. The flow cytometry was used to determine the physiological state of the cell, SEM and TEM were used to observe cell morphological changes and ultrastructure of bacteria. The influence of cell membrane permeability was evaluated by UV spectrophotometry. The results showed that, after high pressure thermal sterilization, the survival rate of Weissella viridescens and Leuconostoc mesenteroides was-4.74 and-6.61lg (CFU/mL), respectively. These two baroduric bacteria appeared growth retardation and lower growth rate in exponential phase under high-pressure thermal sterilization. SEM and TEM results showed high pressure thermal sterilization induced obvious morphologic changes of cells and intracellular cytoplasm aggregate with large electron transmission area. The combination of heat and pressure treatment damaged the cell membrane, and made the cell membrane permeability larger, which caused a significant increase in extracellular ultraviolet absorption content (p<0.001), and the cells would be in a sublethal state. The combination of heat and pressure would cause certain deformation and damage to the cell membrane, which would lead to the flow out of nucleic acid and protein in cell, and the protein denaturation and cytoplasm shrinkage would occur inside the cell, thereby inhibiting the growth and reproduction of the pressure-resistant bacteria.