A large volumetric fraction of icosahedral quasicrystal was gained through ordinary solidification technology in Mg-Zn-Y ternary alloys.The icosahedral quasicrystal in Mg-Zn-Y ternary alloys have two typical morphology features:petal-like,polygon-like.The different features of icosahedral quasicrystal are attributed to their morphology evolution.Alloying composition and cooling rate are major factors affecting the morphology of icosahedral quasicrystal.In the solidification process of quasicrystal alloys,the more the low-temperature phases and the less the cooling rate,the much more easily the changing into the polygon-like morphology from petal-like one takes place.Peritectic reaction occurs during the icosahedral quasicrystal formation which leads to element content difference in primary stage and in final stage of icosahedral quasicrystal evolution.The composition analyses show that Mg content is lower but Zn and Y contents are higher in the primary stage of quasicrystal growth.