The　issues　of　Human-Machine　Interface　(HMI)　of　Virtual　Environment　(VE)　are　discussed　in　view　of　users＇　potential　application　requirements　in　VE.　The　Human-centered　HMI　containing　rich　context　information　is　proposed　by　taking　the　advantage　of　the　abundant　research　findings　of　artificial　intelligence　and　pervasive　computing.　The　technology　of　context-aware　computing　is　introduced　in　this　study　for　providing　initiative　services　mode　as　well.　First,　in　view　of　the　characteristics　of　VE,　the　Web　Ontology　Language　(OWL)　is　adopted　to　model　the　context　information.　Second,　the　modified　ID3　decision-tree　algorithm　is　applied　to　automatically　generate　the　context　rules　of　VE.　Third,　the　polymorphic　proactive　services　model　based　on　context　rules　is　designed.　Finally,　an　example　is　given　to　illustrate　how　to　apply　context　rule-inference　to　realize　proactive　services.　The　experiment　demonstrates　the　correctness　and　effectiveness　of　the　above　mentioned　algorithm　and　model.　©　2014　World　Scientific　Publishing　Company.