H.264/AVC　is　a　high　performance　video　coding　standard　with　higher　compression　and　better　network　compatibility,　which　not　only　has　important　theoretical　value　but　also　shows　wild　application　prospect.　In　order　to　reduce　its　computational　complexity　and　achieve　real-time　application　requirements,　a　multi-stage　fast　intra　mode　decision　algorithm　is　proposed.　In　the　first　stage,　we　choose　the　optimal　mode　from　intra　4x4　and　intra　16x16　by　extracting　the　spatial　features　of　macro-block　using　two-dimension　histogram,　in　combination　with　double-threshold　algorithm.　In　the　second　stage,　the　nine　prediction　directions　in　intra　4x4　mode　are　divided　into　two　groups　and　the　optimal　group　is　selected　by　pre-determination　algorithm　before　coding.　Experimental　results　show　that　the　proposed　algorithm　reduces　the　coding　time　effectively　with　little　degradation　of　image　quality.　©　2011　IEEE.