Objective To investigate the therapeutic effect of long PHILOS locking compression plate on the proximal humerus and humeral shaft fractures. Methods From March 2005 to December 2007, 35 cases with the proximal humerus and humeral shaft fractures were treated with long PHILOS locking compression plate, including 16 males and 19 females aged 29-68 years old (average 54.5 years old). There were 34 cases of fresh and close fracture, and the time from injury to operation was 3-9 days. One case had delayed union of fracture 5 months after receiving T-plates and internal fixation with steel plate. For the proximal humerus fracture, 7 cases had 2 parts of fracture, 19 had 3 parts of fracture, and 9 had 4 parts of fracture according to Neer classification; while for the humeral shaft fracture, 3 cases were classified as A1, 5 as A2, 10 as B1, 3 as B2, 6 as B3, 7 as C1 and 1 as C3 according to AO classification. Postoperatively, Neer scoring system was employed to evaluate the function of shoulder joint and HSS scoring system was adopted to evaluate the function of elbow joint. Results All incisions healed by first intension, and 30 cases were followed up for 12-33 months (average 18.2 months). Postoperatively, 2 cases had symptoms of radial nerve paralysis, which disappeared within 3 weeks; 1 case suffered from humeral head necrosis and received the secondary operation of humeral head replacement; humeral head was reduced evenly in 1 case, and 2 cases felt chronic sl ight pain in shoulder joints and received no further treatment. X-ray films showed 29 cases had fracture heal ing 6 months after operation, and all the patients had bone union 12 months after operation except 1 case receiving humeral head replacement. No such compl ications as screw lossening and internal fixation loosening occurred. By Neer scoring system, 6 cases were graded as excellent, 19 as good, 3 as fair, 2 as poor, and the excellent and good rate was 83.3%. By HSS scoring system, 16 cases were gradedas excellent, 14 as good, and the excellent and good rate was 100%. Conclusion Applying long PHILOS locking compression plate in the treatment of the proximal humerus and humeral shaft fractures provides a sol id fixation and high satisfactory rate with minor compl ications.