The temperature dependence of acoustic velocities, thermal properties, and phonon frequencies, mechanical, electronic, and optical properties for the InPxAsySb1-x-y/InAs system has been studied. The physical properties of the binary components InSb, InP, and InAs that constitute the quaternary alloy were used in this research. The study has been done using the empirical pseudo-potential method (EPM) under the virtual crystal approximation (VCA). The thermal properties, phonon frequencies, and acoustic velocities for the InPxAsySb1-x-y/InAs system under the effect of temperature have not been fully studied. Therefore, we have focused on these properties under the influence of temperature. Due to the lack of the published theoretical and experimental values on these properties, our findings will provide a significant reference for future experimental work.