We try to synthesize InxGa1−xSb nanowires on silicon (100) substrate using InSb and GaSb as source materials and we succeeded. Au film was used as catalysts. The experiment is simple and repeatable. The diameter of the grown nanowires is 60–200 nm and up to 10 microns in length. The grown nanowires have good crystallinity. Due to the doping of indium, we found that the XRD peaks of nanowires were shifted. We have fabricated fully nanostructured device using ultra-long Ag nanowires as electrodes for the I–V characteristic study, and found that the device has photoresponse characteristics and the I–V characteristic curve was asymmetric, we explain that it was due to the asymmetry of this fully nanostructured devices.