Peritectic reaction is frequently encountered in many technologically important materials (e.g., steels, brass, bronze, intermetallic compounds, magnetic materials and YBa₂Cu₃O_x superconductors). Many interesting microstructures have been found during directional solidification of peritectic alloys, which have drawn much attention since last decade. In this work, in order to investigate the growth behavior of Al₃Y phase as a peritectic phase, directioanal solidification experiments at different pulling rates have been performed on Al-53%Y (mass fraction) peritectic alloy. The results show that the primary phase and the peritectic phase both grow continuously, the microstructure, which is parallel to the solid-liquid interface has been found and explained at a low pulling rate (V=1 μm/s). With the growth distance increase, the precipitating solid phase from the liquid at the quenching solid-liquid interface transforms from primary Al₂Y phase to peritectic Al₃Y phase. The interface consists of coarse Al₃Y phase without Al₂Y phase. At relatively high pulling rates, the morphologies of primary Al₂Y phase transit from continuous growth to cellular phase, and further to dendrites with the pulling rate increase. The results also show that the primary phase is enclosed with the serrate peritectic phase, and Al₃Y phase precipitates from the liquid in needle shape at the same time. With the growth distance further increase, Al₃Y phase become thicker and more numerous. In addition, the Al₃Y phase precipitated from liquid transit from needle shape to short rod and lump shape, which distributes around the peritectic structure.