目的　为临床上确定臀部肌肉内注射的最佳部位及深度提供数字化解剖学依据。　方法 （1） 23具防腐标本，解剖观测臀肌注射位置与血管干、坐骨神经的距离及软组织厚度；（2） 6具明胶-氧化铅灌注的新鲜整尸标本，CT扫描后，行盆部三维重建。　结果　三分法臀部肌内注射点处的软组织总厚度为（6.63±1.06）cm，臀肌间隙至髂骨翼骨膜的距离为（4.37±0.62）cm，注射针体距臀上血管主干和坐骨神经的距离分别为（5.87±0.93）cm和（7.46±0.94）cm；十字法臀部肌内注射定位点距坐骨神经的距离为（3.63±0.68）cm。　结论　连线法臀部肌内注射简易而安全，但目前成人常用的注射针头（2.7~4.9 cm）普遍偏短，建议选择针梗长6 cm以上的针头。

Objective　To provide morphological data of an algorithm for optimal the site and needle length for gluteal intramuscular injection in adults.　Methods　(1) Twenty-three embalmed cadavers were injected with red latex. The buttock injection sites were identified as a probe. Dissection, measurement and photography were used to document the precise soft tissue thickness and relationship between the sciatic nerve and the gluteal intramascular injection sites in the gluteal region; (2) Six fresh cadavers underwent whole-body lead oxide injection for three-dimensional reconstruction using a spiral CT scanner and specialized volume-rendering software.    Results    Mean soft tissues thickness at injection site was (6.63±1.06) cm, the depth from intergluteal fissure to iliac periosteum was (4.37±0.62) cm, the depth from skin to intergluteal fissure was (2.26±0.89) cm, the length from injection needle to main trunk of superior gluteal vessels and sciatic nerve was (5.87±0.93) cm and (7.46±0.94)cm respectively in trichotomy way. The length between reference point and sciatic nerve was (3.63±0.68) cm in crossing way.    Conclusions    The finding that buttock subcutaneous fat thickness exceeds the length of the most commonly used needle for intramuscular buttock injection (2.7~4.0cm), suggests that the currently used injection technique may not be therapeutically optimal. We suggest that a needle longer than 6 cm should be used in for intramuscular buttock injections in adults.