Photoacoustic　imaging　is　a　noninvasive　biomedical　imaging　modality　for　visualizing　the　internal　structure　and　function　of　soft　tissues.　In　this　paper　we　present　a　combined　iterative　reconstruction　algorithm　to　recover　the　distribution　of　optical　absorption　coefficients.　Such　a　combination　of　the　simultaneous　algebraic　reconstruction　technique　(SART)　algorithm　and　the　filtered　back　projection　(FBP)　algorithm　bears　the　promise　to　improve　the　image　quality　of　fast　but　not　accurate.　The　different　between　the　present　proposal　and　traditional　ART　algorithm　is　that　we　computer　a　full　error　image　with　FBP,　which　is　used　to　projection　differences　between　original　and　reconstruction　image,　and　to　update　the　solution　in　each　iteration　step.　The　combined　iterative　reconstruction　algorithm　works　well　in　rectification　of　the　measurement　and　converges　quickly　onto　an　accurate　estimate　of　the　distribution　of　absolute　absorption　coefficients.　Numerical　simulations　demonstrate　that　the　proposed　algorithm　effectively　reduces　the　artifacts　and　blurs,　and　yields　better　quality　of　reconstruction　image　than　that　with　FBP　algorithm　in　terms　of　both　accuracy　and　robustness　to　noise.