目的　为背阔肌复合组织瓣转位重建上肢运动功能提供解剖学依据。  方法　通过解剖16侧10%福尔马林液固定成人尸体标本，观察背阔肌形态变化及其起点处与腰背肌的解剖结构关系。使用SPSS 13.0统计软件进行数据统计。  结果　背阔肌起点处肌质薄，肌束分两大部分，肌束方向不一致，胸背神经分两支分别支配。背阔肌起点处与腰背肌表面的胸腰筋膜愈着紧密，此处胸腰筋膜腱膜增厚；背阔肌起点处与腰背肌之间有血管、神经自肌肉深面穿过，解剖位置恒定。  结论　背阔肌解剖形态特点及胸背神经支配特点是肌肉转位后前臂力量不足的主要原因；背阔肌携带起点处的浅层腰背肌肉的背阔肌复合组织瓣可以增强转位术后前臂肌力，且无需吻合血管。

es of latissimusdorsi was observedand the relationship of the origin of the latissimusdorsi with the adjacentmuscles in the lower back was investigated . SPSS 13.0 statistical software was for data processing.　Results　Latissimusdorsi at the beginning of sarcoplasmic thin The latissimusdorsi was thin at the origin, and the muscle divided into two bundles with inconsistent directions respectively innervated by two branches of thoracodorsal nerve. Latissimusdorsi at origin united closely with thoracolumbar fascia, leading to the thickening the thoracolumbar fascia; blood vessels and nerves traveled between the latissimusdorsi and the deeper thoracolumbar muscles with consistent anatomical characteristics.　Conclusion　The anatomy characteristics the latissimusdorsi and thoracodorsal nerve are the main reason for the lack of forearm strength after muscle transposition; The latissimusdorsi composite flap containing at its origin other superficial lower back muscles can enhance the forearm muscle strength after flap transposition without vascular anastomosis.