Topics　in　professional　blogs　mainly　refer　to　specific　techniques.　Today,　professional　blog　websites　have　been　important　information　sources.　However,　information　overload　and　the　uncertainty　of　topic　hotness　evaluation　have　been　obstacles　for　hot　topic　detection.　The　paper　proposes　a　method　of　detecting　hot　topics　in　professional　blogs.　The　proposed　method　is　based　on　the　characteristics　of　the　professional　blogs　and　mainly　analyzes　candidate　topics　that　are　likely　to　be　hot.　First,　a　word　network　based　on　high　frequency　keywords　and　co-occurrences　of　the　keywords　is　constructed,　and　then　the　candidate　topics　are　extracted　by　analyzing　the　structure　of　the　word　network.　The　opinion　networks　with　respect　to　the　topics　in　different　time　intervals　are　subsequently　constructed　for　opinion　analysis.　Finally,　hot　topics　are　identified　by　computing　the　user　participation　degree,　opinion　communication　degree,　and　timeliness　of　the　candidate　topics.　Experimental　results　show　the　proposed　method　is　feasible　and　reasonable.　©　2011　Springer-Verlag.