Durability of CFRP sheet was studied in simulative way under marine environment(such as single factor effect and multi-factor combined effects of salt solution immersion,wet and dry cycles in salt solution,freeze and thaw cycles).The results show that after fast aging under marine environment the relation between stress and strain of CFRP sheet still show typical linearity.The tensile strength of CFRP sheet decreases greatly,the elongation decreases even more greatly whereas the elastic modulus decreases slightly.The multi-factor combined effects on tensile strength and elastic modulus of CFRP sheet are stronger than single factor effect.