The mechanical characteristics of amorphous As2Se3:Sn prepared by thermal evaporation in vacuum on glass substrates heated at Tsubstr = 100 oC are investigated. It was established that the hardness H of amorphous thin films is generally higher than the hardness of bulk samples of the same chemical composition. Because the composition of chalcogenide glass (ChG) determine the kind of structural units and the mean coordination number, in the present work the amorphous films of the As2Se3:Snx (x=0÷10.0 at.% Sn) of chalcogenide system were investigated. The combination of depth sensing indentation and band-gap illuminations has been used to study the photoplastic effect in chalcogenide glasses. The prominent photoplastisity of thin films has been revealed through hardness deviations during nanoindentations under light illuminations from those ones which have been observed for the materials on the darkness. Some optical properties and the modification of optical parameters (optical band gap Eg, absorption coefficient α, refractive index n) under light irradiation and heat treatment of the amorphous As2Se3:Snx thin films thin films, and the relaxation of photodarkening effect under the light exposure also was investigated.