Abstract: The role of Sb element in Al-Si alloys was summarized and analyzed. It can be concluded that Sb element has influence on primary α-Al dendrite and eutectic Si of Al-Si alloy. The modification of Sb element is related to cooling rate,and there is a phenomenon of over-modification. Sb element forms Al Sb, Mg₃Sb₂, etc., which can lead to Sb over-modification. Sb element is a long-acting modifier, has a certain incubation period, good remelting and no incubation period after remelting. The study of Sb modification mechanism has not consistent conclusion. Sb element also affects the fluidity of Al-Si alloys. Sb element will cause certain harm to human body and environment. The shortcomings of the existing research and the future research direction were also pointed out.