Many　actions　have　been　carried　out　to　promote　the　low-carbon　society　construction　in　China,　emission　trading　system　(ETS)　and　energy　efficiency　trading　(EET)　are　two　typical　instruments　during　the　past　five　years.　This　paper　focused　on　the　coexistence　between　ETS　and　EET　aiming　to　explore　whether　policy-mix　could　enhance　industries＇　interests　through　the　partial-equilibrium　model.　The　results　showed　that　when　overlapping　transaction　scope　is　allowed,　the　shadow　price　of　energy　saving　is　certain　for　the　industries.　When　is　not,　setting　up　the　policy-mix　would　not　improve　energy　savings　of　industries　but　would　make　the　two　trading　systems　complementary,　via　the　internal　mechanism　of　the　policy-mix　and　providing　multiple　policy　options.　The　analysis　indicated　that　EET　and　ETS　could　coexist　and　yield　better　results.　Energy　saving　quota　and　CO2　quotas　can　be　mutually　recognized　in　a　certain　method　avoiding　the　repeated　accounting　between　two　quotas,　which　will　not　increase　the　burden　of　enterprises　but　encourage　them　to　conduct　flexible　emission　reduction　to　enhance　the　competitiveness.　(c)　2021　The　Author(s).　Published　by　Elsevier　Ltd.