Abstract: Abstract: Penaeus vannamei is one of the three major cultured shrimps in the world, which has high nutritional and commercial value, containing various mineral elements, high proteinlow fat and a good proportion of fatty acids. Alive, fresh, frozen and preserved Penaeus vannamei are main products in retail and wholesale market. Among them, ready-to-eat shrimp was one of popular products by the way of low temperature drying, mild sterilization and vacuum packaging and other minor processing, which has high nutrition value and easy to carry. However, the vacuum packaging ready-to-eat shrimp meat is easy to spoil and difficultly to store during processing, packaging and distribution. In previous study, the shelf life and dominated spoilage organisms of ready-to-eat shrimp stored at ambient temperature were carried out, and Bacillus spp.(eg.Bacillus licheniformis) isolated from them at the end of shelf life were identified as dominated spoilage organisms. In order to investigate sterilization effects and mechanisms of microwave sterilization on Bacillus licheniformis spores isolated from ready-to-eat shrimp meat, the effects of different temperatures (including 80, 85, 90, 95 and 100 ℃) and different treated time by the microwave sterilization on Bacillus licheniformis spores were carried out, which water bath sterilization was used as a control group. The differences and changes of Bacillus licheniformis spores in physico-chemical properties before and after water bath sterilization and microwave sterilization were analyzed. The results showed that at the same sterilizing temperature, the effects of microwave sterilization on Bacillus licheniformis spores were significantly different with water bath sterilization. Bacillus licheniformis spores were finally killed by means of microwave and water bath sterilization, but the microwave sterilization needed only two minutes, the water bath needed at least five minutes. R2 analysis showed that the weibull model (R2>0.89) could better fit the inactivation curves of the two sterilization methods, but the linear model was more intuitive than weibull model. The time of protein and nucleic acid leakage in the spore suspension caused by the microwave treatment was earlier than that of the water bath, microwave treatment reached the maximum value of OD260 nm and OD280 nm within 10 min, while water bath treatment reached the maximum value of OD260 nm and OD280 nm within 40 min. Compared with the water bath, the spore germination curve after microwave treatment had a longer lag phase, 95℃ water bath process 100 min, lag time can extend 8 min, and 95 ℃ with microwave for 10 min, spore germination. The difference of microwave sterilization water bath sterilization under different temperatures and time were investigated. It will provide theoretical and practical basis for optimization of product sterilization technology, targeted sterilization and reduction of bag expansion rate. Meanwhile, the mechanisms and dynamical equations of different sterile means are also further studied.