Mechanical properties of domestic 374 stainless steel have been evaluated fur membrane material used in LNG storage tank. LNG tank is operated around -162$^{circ}C$. The temperature of membrane depends on LNG level. Accordingly, the membrane material is deteriorated by variation of liquid pressure and temperature. Tensile test and fatigue life test were performed at room temperature and -l62$^{circ}C$ per code requirements. Especially the biaxial fatigue life test was conducted with shaped membrane sheet at a thermal strain of $Delta$T=190$^{circ}C$ The test results obtained with the domestic 304 stainless steel showed better properties compared to the values required by code.