Abstract: Objective: To investigate the correlation of Muller classification and prognosis of the proximal humerus fractures in young people.Methods: Among 180 proximal humerus fractures patients,the A1 fracture in 20 cases,A2 fracture in 40 cases,A3 fracture in 80 cases and B fracture of 40 cases were identified accorded to Muller classification.All patients were treated with small incision minimally invasive surgical fixation.Results: All fractures were primary healing.The fracture healing time in A1 and A2 fracture patients were significantly shorter than that in other patients(P<0.05).The excellent and good rates of shoulder function in A1,A2,A3 and B fractures patients were 90.0%,80.0%,75.0% and 62.5% after 3 months of operation,respectively,the difference of which in each group was not statistically significant(P>0.05).After 3 months of operation,the differences of the incidences of the vascular injury,infection,bleeding and plate break between four type fractures were not statistically significant(P>0.05).The differences of the pain,daily life,range of motion and strength scores in different Muller classification patients were statistically significant(P<0.05 to P<0.01).Conclusions: The operation healing rate of proximal humerus fracture in young people is high.The application of Muller classification can effectively guide the operation,and judge the prognosis in short-term.With the increasing with the Muller classification,the prognosis of patient is getting better.