BACKGROUND:: The domestic and international literatures have confirmed that the internal fixation of long proximal humeral locking compression plate has satisfactory effect on the treatment of proximal humerus fractures. OBJECTIVE:: To investigate the clinical effect of internal fixation of long proximal humeral locking compression plate on the treatment of proximal humerus and humeral shaft fractures. METHODS:: Sixteen cases with the proximal humerus and humeral shaft fractures were treated with long proximal humeral locking compression plate internal fixation, including seven males and nine females, aged 45-83 years old (average 71 years old). According to the Neer classification of proximal humerus, five cases had two parts of fracture, eight cases had three parts of fracture, and three cases had four parts of fracture; and according the AO classification of humeral shaft, five cases were classified as A1, six cases as B1, two cases as B2, two cases as C1 and one case as C3. Postoperatively, Constant-Murley scoring system was employed to evaluate the function of shoulder joint, and then the percentage was calculated for the corresponding evaluation. Modified Hospital for Special Surgery scoring system was adopted to evaluate the function of elbow joint. RESULTS AND CONCLUSION:: All cases were followed-up for 12-24 months (average 14.9 months), and all the cases had bone union in 8-17 weeks (average 12.1 weeks) after operation. Postoperatively, two cases suffered from fat liquoring, but healed after dressing. One case had the symptoms of radial nerve paralysis, one case had subacromial impingement syndrome and improved after treatment. No complications such as screw loosening, screw cut out or humeral head ischemic necrosis were observed. After treated for 12 months, the Constant-Murley score on fracture side was 76.87 in average (ranged 65-90), which was 83.41% in average (ranged 71.4%-93.8%) to the normal side, the clinical outcomes on shoulder were excellent or good in 15 cases, satisfied in one case. By Hospital for Special Surgery scoring system, 13 cases were graded as excellent, three cases as good, and the excellent and good rate was 100%. Long proximal humeral locking compression plate for the treatment of the proximal humerus and humeral shaft fractures provides solid fixation and high satisfactory rate with minor complications.