We　study　the　relay-based　communication　schemes　for　cooperative　spectrum　sharing　among　multiple　primary　users　(PUs)　and　multiple　secondary　users　(SUs)　with　incomplete　information.　Inspired　by　the　matching　theory,　we　model　the　network　as　a　matching　market.　In　this　market,　each　PU　proposes　a　certain　proposal　representing　a　combination　of　relay　power　and　spectrum　access　time　to　attract　the　SUs,　while　each　SU　maximizes　its　utility　by　selecting　the　most　suitable　PU.　We　derive　the　sufficient　and　necessary　conditions　for　a　stable　matching　in　which　none　of　the　PUs　or　SUs　would　like　to　change　its　decision.　We　further　establish　a　distributed　matching　algorithm　(DMA)　and　a　DMA　with　utility　increasing　(DMA-UI)　to　achieve　the　equilibria　in　partially　incomplete　and　incomplete　information　scenarios,　respectively.　Moreover,　we　provide　detailed　discussions　on　the　implementation　of　the　distributed　algorithms　in　practical　networks.　Simulation　results　show　that　the　losses　of　PUs＇　total　utilities　caused　by　incomplete　information　are　diminished　when　the　number　of　SUs　increases.　Specifically,　the　effects　of　the　incomplete　information　are　reduced　as　the　competition　among　SUs　(PUs)　is　more　intensive　than　that　among　PUs　(SUs).　©　1972-2012　IEEE.