Liquefied Natural Gas (LNG) tank is the important equipment in storage LNG. There has been a lot of research results abroad, but lack of seismic studies for the LNG tank in China. Domestic structural designers also have an urgent need for internal force and deformation law of LNG tanks under a variety of dynamic loads. This study focused on vibration characteristics and seismic response of a shell of LNG tank. Using ANSYS creat finite element model, obtain natural frequency and vibration mode etc. According to requirements of Chinese "code of building seismic design", analyze this shell of LNG tank of unidirectional horizontal seismic response under the action of selected three kinds of seismic waves. Time-history curves of LNG tank’s displacement, acceleration, stress distribution law under the action of selected three kinds of seismic waves are obtained.