Abstract: The effect of trace elements in ZA27 cast alloy,such as Mg,Cu,RE,Ti and thickness of.castings,pouring temperature,modification on the solidification characters of ZA27 cast alloy were studied.The experimental results show that the thickness of castings is the primary factor which affecting the solidification of ZA27 alloy.The solidification characters of ZA27 alloy can be improved by the suitable addition of Ti,and can also be changed with the change of pouring temperature and modification.According to the experimental results,the suitable parameters of technology are recommended.