Abstract: The boiling liquid expanding vapor explosion (BLEVE) is an explosion caused by bulk boiling and rapid expanding of superheated liquid. It often happens in liquefied petroleum gas (LPG) tanks during stationary and transportation storage. Based on experimental results from the Health and Safety Executive of England on LPG tanks under pool and jet fires, the authors investigated the thermo-physical processes including internal pressure change, wall temperature change and LPG mass release in LPG tanks as well as the relations among the dependent variables. Physical and mathematical models were presented in PLGS99 (pressure liquefied gas simulation) software to simulate the temperature and pressure responses of LPG tanks. The predictions were validated by experimental data and the explosion mechanism of LPG tanks caused by BLEVE was analyzed.