This　paper　presents　an　efficient　hybrid　simulated　annealing　algorithm　for　three　dimensional　container　loading　problem　(3D-CLP).　The　3D-CLP　is　the　problem　of　loading　a　subset　of　a　given　set　of　rectangular　boxes　into　a　rectangular　container　so　that　the　stowed　volume　is　maximized.　The　algorithm　introduced　in　this　paper　is　based　on　three　important　algorithms.　First,　complex　block　generating,　complex　block　can　contain　any　number　boxes　of　different　types,　which　differs　from　the　traditional　algorithm.　Second,　basic　heuristic,　which　is　a　new　construction　heuristic　algorithm　used　to　generate　a　feasible　packing　solution　from　a　packing　sequence.　Third,　simulated　annealing　algorithm,　based　on　the　complex　block　and　basic　heuristic,　it　encodes　a　feasible　packing　solution　as　a　packing　sequence,　and　searches　in　the　encoding　space　to　find　an　approximated　optimal　solution.　1500　benchmark　instances　with　weakly　and　strongly　heterogeneous　boxes　are　considered　in　this　paper.　The　computational　results　show　that　the　volume　utilization　of　hybrid　algorithm　outperforms　current　excellent　algorithms　for　the　considered　problem.