Tension test specimen and its filling and feeding system of nationl standard specification for casting AI alloy are redesigned.Solidification of the redesigned tension test specimen was simulated with computer.The specimen has been used in large scale commercial production of casting A1 alloy since 1994.The result show that the redesigned specimen is reasonable,thus could be bring into the new casting A1 alloy standard system,and popularized in the field of casting A1 alloy.