Liquid storage tanks are quite important structures that are widely used in different industrial plants. Because of their recent performance along sever earthquakes; there is a strong possibility that these structures are under possible danger of devastating damages. Hence, in this study, the seismic behavior of these structures with an emphasis on their vulnerability under different condition is analyzed. For this purpose, an oil industry plant in the south of Iran is considered and five different tanks with different dimension are chosen. Three significant parameters which are usually taken into account for evaluation of tanks are investigated. These Criterions are including: 1) Sliding, 2) Elasto-Plastic buckling (Elephant foot buckling), 3) Tank roof damage. Finally, the results show that al the studied tanks are quite safe for Elephant foot buckling criteria. However, for the two other criteria the results was not like Elephant foot buckling criteria.