目的　建立正常成人CT轴位扫描眼外肌的直径标准、眼外肌群直径总和与颧骨间距比值及眼球的正常位置。方法　从10 0例正常成人共 2 0 0个眼球结构中 ,在轴位CT上分别测量眼外肌的直径、颧骨间距、从颧骨间平面到眼球后缘的距离、球后至眶尖的距离及视神经鞘的宽度 ,同时分析眼外肌群直径总和与颧骨间距的比值。结果　眼外肌正常直径范围 :内直肌 2 .7～ 5 .2mm ,平均 4.0mm。外直肌 1.8～ 4.9mm ,平均 3.4mm。下直肌 5 .4～ 9.1mm ,平均 7.8mm。上直肌群 6 .7～ 10 .2mm ,平均 8.5mm。视神经鞘为 3.1～ 5 .6mm ,平均 4.4mm。眼球后缘正常位置为颧骨间线后 8.7mm(范围 5 .4～ 11.9mm) ,球后至眶尖 33mm(范围 2 4～ 42mm) ,眼外肌总和与眶骨间距比值为 0 .2 3(范围 0 .19～ 0 .2 6 )。结论　CT测量眼眶结构简便易行 ,并检出测量的参考层面标准 Objective To establish the diameter standard of oculomotion scan of normal adults, the ratio between the total diameter of extraocular muscles and the distance between zygomatic bones and the normal eyeball. Methods The diameter of the extraocular muscle, the distance between the zygomatic bones, the distance from the zygomatic plane to the posterior edge of the eyeball were measured on the axial CT from 200 eyes of 100 normal adults. The distance from the ball to the orbital tip And the width of the optic nerve sheath, while analyzing the ratio of the total diameter of the eye muscle group to the zygomatic bone space. Results Ophthalmic normal diameter range: 2 ~ 7 ~ 5. 2mm medial rectus muscle, with an average of 4.0mm. Outside the rectus muscle 1.8 ~ 4.9mm, an average of 3.4mm. Lower rectus muscle 5.4 ~ 9.1mm, an average of 7.8mm. Upper rectus muscle group 6 .7 ~ 10 .2mm, an average of 8.5mm. Optic nerve sheath 3.1 ~ 5 .6mm, an average of 4.4mm. The normal posterior margin of the eyeball was 8.7 mm (range 5.4 ~ 11.9 mm) posterior to the zygomaticus, 33 mm (range 2-4 4 mm) posterior to the orbital apex, and the ratio of total extraocular muscle to orbital bone space was 0.2 3 (range 0 .19 ~ 0 .2 6). Conclusions CT measurement of the orbital structure is simple and easy, and detects the reference level of measurement standards