The effectofannealinginnitrogenatmosphereonstructuralandelectricalpropertiesofseleniumrich CdSe (SR-CdSe)thinfilmsdepositedbythermalevaporationontoglasssubstrateswerestudied.X-ray diffraction(XRD)patternsshowedthattheas-preparedfilmswereamorphous,whereastheannealed filmswerepolycrystalline.AnalyzingXRDpatternsrevealsthecoexistenceofbothSeandCdSe crystallinephaseswhichexhibitsahexagonalstructure.Themicrostructureparameters(crystallite size, microstrainanddislocationdensity)werecalculatedforannealedfilms. Temperaturedependence(300–500K)ofd.c.conductivitywasstudiedforas-preparedand annealedthinfilms.Theexperimentalresultsindicatethattheelectricalconductiontakingplace throughthermallyactivatedprocess.Athighertemperatures,electricalconductionforas-preparedfilm is takingplaceintheextendedstateswhilelocalizedstatesconductioninthebandtailsismostlikelyto take placeforannealedfilms.Regardingthelowertemperaturerange,conductionbyhoppinginthe localizedstatesneartheFermilevelisfoundtobedominant.Thus,conductivitydatainthisrangewas analyzedusingMott’svariablerangehoppingconduction,whereMott’sparameterswerecalculatedfor SR-CdSe thinfilms.