InAs_0.6P_0.4epilayers grown by low-pressure metal organic chemical vapor deposition (LP-MOCVD) on InP (100) substrate are investigated. The influence of growth temperature on crystalline quality of InAs_0.6P_0.4epilayer is characterized by scanning electron microscopy (SEM), Hall measurements, photoluminescence (PL) spectra, and the Raman properties are analyzed by Raman scattering spectrum. The characterization results show that the crystalline quality and Raman property of InAs_0.6P_0.4epilayers have close relation to the growth temperature. It indicates that 530 °C is the optimum growth temperature to get good quality and properties of InAs_0.6P_0.4epilayers.