We prepared polycrystalline AgInSe₂ thin films by vacuum evaporation on Si(100)  substrate at a high temperature using the stochiometric powder. The thin films were characterized by X-ray diffraction and Uv-vis-NIR spectroscopy .For the fabrication of densely distributed one dimensional nanostructures of Silver Indium selenide on Si substrates, the thermally evaporated films of  AIS  on Si (1 0 0) substrate  were irradiated by incident 200MeV Ag⁺ ions  at a fluence of  5 X 10¹¹ Ion/cm². At elevated substrate temperatures AIS were featured by the nanorods -like structure. The optical and structural properties of the irradiated films were studied using  UV–visible absorption spectroscopy , atomic force microscopy (AFM) , Field emission scanning electron microscopy (FESEM ) and XRD .The controlled fabrication of such densely distributed one dimensional nanorods  on Si substrate  using ion beam technique, we believe, would open up a variety of applications such as nanoelectronics and optoelectronics devices.