An　enhanced　active　power　adjustment　model　is　developed　for　reliability　evaluation　of　the　hybrid　AC/DC　power　system.　The　power　flow　on　the　high　voltage　direct　current　(HVDC)　line　is　embedded　as　an　optimal　variable　in　the　classical　active　power　adjustment　model,　which　will　help　to　analyze　the　HVDC　interconnections　as　tie　lines　among　regions　more　conveniently.　The　proposed　model　is　applied　in　the　modified　IEEE-RTS　system,　where　a　HVDC　line　is　incorporated　as　a　tie　line　between　two　regions.　The　annualized　system　and　nodal　reliability　indices　are　calculated.　Furthermore,　we　may　determine　the　optimal　transmission　capacity　on　the　HVDC　line　by　sensitivity　analysis　from　the　view　of　reliability,　which　will　provide　a　useful　reference　for　the　planners　and　designers.