Abstract: 0bjective To analyze the maxillofacial morphological characteristics of patients with abnormal upper lateral incisors．Methods 120 patients with abnormal upper lateral incisors were divided into two groups and were analyzed cephalometrically: group A:60 cases of typeⅠpeg-shaped upper lateral incisors; group B: 60 cases of type Ⅱ microdontia upper lateral incisors．Students’t-test was used for data analysis．Results Group A showed significantly smaller SNA、ANB、Ptm-A(mm)、U1-SN、L1-NB、UL-EP and increased SNB、PP-GoGn、SN-MP、Y axis、U1-L1、U1-NA、L1-MP and Z angle（P<0.05）while Group B showed significantly smaller SNB、PP-GoGn、SN-MP、SN-MP、Y axis、U1-L1、angle and increased ANB、L1-NB、L1-MP（P<0.05）.Conclusions Most patients with TypeⅠpeg-shaped upper lateral incisors showed Class Ⅲ skeletal pattern with retrusive maxilla and most patients with Type Ⅱmicrodontia upper lateral incisors showed Class Ⅱ skeletal pattern with retrusive mandible. Patients with the two types of abnormal upper lateral incisors showed different maxillofacial morphological characteristics.