Indium aluminum arsenide(InAlAs) was grown by molecular beam epitaxy on (001) indium phosphide (InP) substrate and the effects of growth temperature on the properties of epitaxial layers were studied. In the temperature range of 370-$400 ^{circ}C$, we observed that the surface morphology, optical quality and structural quality of InAlAs epilayers were improved as growth temperature increased. However, the InAlAs epilavers grown at $430 ^{circ}C$ have the bad surface morphology and show the same trends as structural and epical quality. As a result of these measurements, it is suggested that the InAlAs epilayers of very good properties can be grown at $400 ^{circ}C$.