The directionally solidifi ed microstructure of Sn-16%Sb hyperperitectic alloy has been investigated at various solidifi cation rates using a high-thermal gradient directional solidif ication apparatus. The results indicate that the solidifi cation microstructure consists of hard primary intermetallic SnSb phase embedded in a matrix of soft peritectic β-Sn phase. The primary SnSb phase exhibits faceted growth with tetragonal or trigonal shapes. At the same time, the primary SnSb phase is ref ined with an increase in the solidif ication rate and dispersed more uniformly in the matrix of β-Sn phase. The volume fraction of the SnSb phase fi rstly decreases and then increases when the solidif ication rate increases in directional solidif ication of Sn-16%Sb hyperperitectic alloy. The directionally solidifi ed microstructure of Sn-16% Sb hyperperitectic alloy has been investigated at various solidifi cation rates using a high-thermal gradient directional solidification apparatus. The results indicate that the solidifi cation microstructure consists of hard primary intermetallic SnSb phase embedded in a matrix of soft peritectic β-Sn phase. The primary SnSb phase exhibits faceted growth with tetragonal or trigonal shapes. At the same time, the primary SnSb phase is refined with an increase in the solidification rate and dispersed more uniformly in the matrix of β-Sn phase. The volume fraction of the SnSb phase fi rstly decreases and then increases when the solidification rate increases in directional solidification of Sn-16% Sb hyperperitectic alloy.