Objective To establish an animal model of unilateral alveolar cleft similar with clinical patients and study the effects on the growth of maxilla during the period of rapid development.Methods Twenty dogs（7 weeks old） were divided into the control group（n=10） and the experimental group（n=10）.The dogs experimental group were operated to create a unilateral alveolar cleft.The data of maxillofacial morphology such as the length,width and height of the foreside,middle and back of maxilla via three-dimensional reconstruction CT to evaluate the effects on the growth of maxilla 12 weeks were measured after operation.Results The foreside and middle length,the foreside width and the foreside height of the maxillary were decreased in experimental group（P <0.05）.Conclusion The unilateral cleft alveolar without early intervention plays an important role in maxillary aberration.