In this work, the one step electrodeposition process was used to prepare Ag-In-Se thin films. The films were deposited at room temperature from a bath containing 1-3x10-3 M AgNO 3 , 6x10-2 M InCl 3 and 3x10-2 M of H 2 SeO 3. The KSCN at a concentration of 0.681 M was used as complexing agent. The pH value of the solution was 1.4. Applied potentials to SCE were chosen between-0.3 V and-1.1 V. Films were deposited onto molybdenum/glass and ITO/glass substrates. We showed that the films' compositions are strongly function of the growth conditions. Heat treatment at 320 °C during 30 minutes under nitrogen led to AgInSe 2 chalcopyrite p-type semiconductor. Also, the morphology and crystallinity of the films is improved by annealing. AgInSe 2 films deposited on indium tin oxide showed a band gap value of about 1.24 eV.