Wireless　video　streaming　poses　great　challenges　due　to　the　time-varying　characteristics　of　wireless　channels　and　limited　network　resources.　In　this　paper,　we　investigate　an　optimal　bit　allocation　scheme　for　streaming　the　stored　MPEG-4　FGS　(Fine　granular　scalability)　bit-stream　from　the　video　server　to　the　clients　over　wireless　channel,　which　can　dynamically　adapt　to　the　time-varying　channelconditions.　MPEG-4　FGS　and　RS　(Reed-solomon)　code　have　been　employed　as　the　source　coding　and　channel　coding　respectively.　For　MPEG-4　FGS,　the　reconstructed　image　quality　is　proportional　to　the　number　of　decodable　bits　from　the　enhancement　layer.　Therefore,　to　achieve　the　best　reconstructed　quality　at　the　decoder　under　a　certain　channel　condition,　we　propose　a　decodable　rate　maximized　criterion　to　optimally　determine　the　truncate　rate　of　the　MPEG-4　FGS　bit-stream　and　the　channel　coding　rate.　The　base　layer　and　different　parts　of　the　enhancement　layer　of　MPEG-4　FGS　compressed　bit-stream　are　protected　unequally　according　to　their　importance　degree.　Experimental　results　show　that,　compared　with　fixed　Unequal　error　protection　(UEP)　and　fixed　Equal　error　protection　(EEP),　the　proposed　method　can　achieve　a　better　performance　under　various　channel　conditions.