Analyzing　and　researching　microblog　text　and　microblog　context,　we　propose　a　Chinese　microblog＇s　semantic　expansion　model　based　on　specific　context.　Firstly,　on　the　basis　of　analysis　of　microblog　type,　microblogs　are　classified　into　six　categories:　information-publish　microblogs,　journaling　microblogs,　sharing　microblogs,　forwarding　microblogs,　commentary　microblogs　and　interactive　microblogs.　For　information-publish　microblogs,　we　propose　a　Chinese　microblog＇s　semantic　expansion　model　based　on　specific　context.　Select　forwarding　comment　as　specific　context.　Microblog＇s　effective　forwarding　information　is　added　to　microblog　text　for　supplementing　the　microblog＇s　semantics　and　improving　the　problem　of　data　sparseness.　The　results　of　microblog　classification　performance　evaluation　show　that　the　model　enhances　the　microblog　classification　performance.　©　2014　IEEE.