InAsSb epitaxy had been obtained on(100) GaSb substrate by a home-made low pressure MOCVD system.The characteristic of InAsSb epitaxy was investigated by means of x-ray diffraction technique,optical microscopy and scanning electron microscopy(SEM),and electron microprobe analysis(SEM).And the dependence of surface morphology and solid composition of epitaxy on growth temperature,Ⅴ/Ⅲ ratio and buffer layer is studied.High quality mirror-like surfaces with a minimum lattice mismatch was obtained.