Abstract　In　this　paper,　a　thin　layer　of　high　work　function　CuS　was　introduced　to　the　interface　between　the　anode　and　hole　transporting　layer　(HTL)　to　modify　the　indium　tin　oxide　(ITO)　anode.　Modified　ITO　substrates　possess　a　higher　work　function,　a　lower　sheet　resistance　and　a　negligible　loss　in　transparency.　More　importantly,　a　thin　layer　of　CuS　can　also　benefit　for　the　hole　transporting　of　the　device.　Polymer　solar　cells　(PSCs)　utilizing　modified　ITO　anodes　exhibit　a　significant　enhancement　in　power　conversion　efficiency　(PCE)　and　air　stability　compared　to　devices　with　normal　ITO　anodes.　This　anode　modification　strategy　applies　to　different　active　layer　systems.　Anode-modified　devices　with　poly　(3-hexylthiophene)　(P3HT)　and　[6,6]-phenyl-C61-butyric　acid　methyl　ester　(PC61BM)　as　the　active　layer　exhibit　a　PCE　of　3.5%,　while　poly(4,8-bis(5-(2-ethyl-hexyl)-thiophene-2-yl)-benzo[l,2-b:4,5-b′]　dithiophene-alt-alkylcarbonyl-thieno[3,4-b]thiophene)　(PBDTTT-C-T)　and　[6,6]-phenyl-C71-butyric　acid　methyl　ester　(PC71BM)　system　shows　a　PCE　of　7.4%.　As　a　result,　this　work　provides　a　good　compatibility　for　modification　of　ITO　by　a　thin　layer　of　CuS　in　PSCs　to　achieve　better　performance.　©　2015　Elsevier　B.V.　All　rights　reserved.