Abstract: Vacuum cooling is a complicated heat and mass transfer process supported by various theories such as dif-fusion,heat transfer,mass transfer and phase change.Based on the conse rvation of mass and energy,a simplif ied mathe-matical model was developed to predi ct the variations of temperature and mass loss during vacuum cooling.The predicted temperature variations and mass loss are compared with the measured valu es.It showed that the simulation results agreed with the experimental data well.The deviation between the simulated and the experimental mass loss is about 5%.The mathe-matical model can be used to predict the variations of temperature and mass loss for understanding the mechani sm of vacuum cooling.