Abstract: Objective: To study the level of miR-595 in serum of patients with mandibular prognathism during growth period and its relationship with mandibular growth and ossification. Methods: The research chose 83 skeletal class Ⅲ malocclusion (23 mixed dentition, 60 early permanent dentition) and 92 normal controls (24 mixed dentition, 68 early permanent dentition), using RT-PCR to detect miR-595 levels in two groups and TargetScan software to predict its possible target genes. Results: Expression of miR-595 in mandibular prognathism group was down regulated. There was negative correlation between miR-595 and mandibular growth with statistical differences (P＜0.01). Conclusions: miR-595 might have inhibitory effect on mandibular growth and ossification through target gene.