With　the　information　explosion　speeds　up　the　increasing　of　computing　complexity　rapidly,　the　traditional　centralized　computing　patterns　are　under　great　pressure　to　process　those　large-scale　distributed　information.　However,　the　agent-based　computation　and　high-level　interaction　protocols　foster　the　modern　computation　and　distributed　information　processing　successfully.　The　multi-agent　system　(MAS)plays　an　important　role　in　the　analysis　of　the　human-interaction　theory　and　model　building.　This　study　focuses　on　the　formal　description　of　MAS,　the　conflict-resolving　mechanisms　and　the　negotiation　in　MAS.　In　this　paper,　we　present　a　formalism　for　reasoning　about　the　interaction　of　multi-agent　system,　which　is　MAS　model　based　on　negotiation　axiom　system　of　capability　and　thought　(CTN　system).　We　first　present　the　semantic　frame　and　define　the　global　states,　the　class　of　the　CTN　system,　the　running　and　reachable　states　for　the　CTN　system.　Then　we　present　the　axiomatic　of　negotiating　logic.　We　also　prove　the　Logical　Consistency　and　Completeness　of　the　CTN　system　and　discuss　the　conflict-resolving　mechanisms.　The　semantic　of　CTN　model　is　intuitive,　rational　and　natural,　and　the　CTN　model　is　a　formal　description　by　integrated　the　ability　and　thought　status　of　Agent.　©　2005　IEEE.