Objective To investigate features of maxillary morphology in unilateral cleft lip and palate (UCLP) with maxillary retrusion and the dissimilarities of retruded maxilla.Methods Craniofacial measurements were done in 32 UCLP adult patients with maxillary retrusion (GC), 24 adult patients in class Ⅲ (GⅢ), and 32 healthy adults (GN).The CT slice data was reconstructed into a 3D video model and measured by Mimics 16.01.Results The maxillary volume (GM) and the volume composed of maxilla and maxillary sinuses (GT) were significantly smaller (P<0.05) in GC.The anterior and posterior parts of the maxillary length (A1-P3M⊥CP and P3M-P6M⊥CP) and overall maxillary length(A1-P6M⊥CP)at the dental level were all significantly reduced (P<0.05).There was no significant difference of the distances of A1⊥CP between the GC and GⅢ groups, while the P3M-CP and P6M-CP in the GⅢ group were significantly shorter (all P<0.05).The anterior and overall maxillary length at the dental level (A1-P3M⊥CP and A1-P6M⊥CP) in the GC group was significantly smaller than that in the GⅢ group (all P<0.05).Conclusions The decreased prominence of maxillary complex could be caused by the shortened maxillary length in UCLP patients;the posterior position of the maxilla is more obvious than that of GC group in class Ⅲ patients.