In　this　work,　small-sized　CuS　nanoparticles/N,　S　co-doped　rGO　composites　(CuS@N/S-G-C-n)　are　synthesized　by　a　facile　route　with　the　metal-containing　ionic　liquids　(MILs)　[C(n)MMim](2)[CuCl4]　(n　is　6,　8,　10　representing　the　number　of　C　atoms　in　the　alkyl　chain　of　imidazolium　cation)　as　the　precursors.　In　the　composites,　the　CuS　nanoparticles　with　small　size　of　sub-20　nm　are　homogeneously　dispersed　in　nitrogen　and　sulfur　co-doped　reduced　graphene　oxide　(rGO).　The　highly　dispersed　nanosized　CuS　are　embedded　on　excellent　conductive　doped　rGO　substrates　to　supply　not　only　large　quantity　of　accessible　active　sites　for　lithium-ion　insertion　but　also　short　diffusion　length　for　lithium　ions,　while　the　N　and　S　co-doping　in　rGO　can　efficiently　restrain　the　polysulfides　dissolution　and　circumvent　the　volume　expansion/contraction　associated　with　lithium　insertion/extraction　during　charge-discharge　processes.　Bestowed　by　these　advantages,　the　CuS@N/S-G-C-n　composites　exhibit　enhanced　electrochemical　performance　for　lithium　storage.　Especially,　when　[C(6)MMim](2)[CuCl4]　is　chosen　as　the　precursor,　the　obtained　electrode　material　CuS@N/S-G-C-6　delivers　a　reversible　capacity　as　high　as　603.5　mAh　g(-1)　at　200　mA　g(-1)　after　300　cycles　and　530　mAh　g(-1)　at　2　A　g(-1)　after　1000　cycles.