目的　探讨共同性外斜视矫正术后的远期欠矫问题。方法　对 3 97例外斜视经手术矫正为正位的病人观察 3年的结果进行分析。结果　 3年后 2 41人为正位 ,1 5 4人外斜视 >-8△ ,其中 5 8人≥ -1 5 △ 。病人发生外斜视的年龄 ,控制外斜视的能力及手术适度过矫与远期眼位有关。结论　共同性外斜视矫正术后的欠矫是普遍存在的 ,欠矫可以发生在术后任何时间 ,远期欠矫很难避免。发病晚 ,手术适度过矫及间歇性外斜视的病人的远期欠矫率较低。 Objective To explore the long-term undercorrection after common exotropia. Methods The 3-year results of 3 97 cases of patients with strabismus corrected by surgery were analyzed. Results Three years later, 41 were positive and 154 were exotropia> -8 △, of which 58 were ≥ -1 5 △. Patients with exocervical age, the ability to control exotropia and surgery moderate overcorrection and long-term eye position. Conclusions Undercorrection after common orthotropia is common, and undercorrection can occur at any time after surgery. It is difficult to avoid long-term undercorrection. The incidence of late surgery moderate overcorrection and intermittent exotropia in patients with long-term under-under-correction rate is low.