The three part or four part fractures of proximal humerus generally need the operative treatment, but the anatomical reduction and internal fixation is not easy. Resently many studies suggest that the firm fixation and early permission of joint motion is good method of treatment. From Jan. 1985 to Jul. 1990, we experienced 28 operations for the three or four part fractures of proximal humerus. The results were summarized as follows;1. There were 17 three-part fractures, 4 four-part fractures, 1 three-part fracture-dislocation, 4 four-part fracture-dislocations and 2 head splitting fractures following to Neer's classification. 2. The excellent or satisfactory results were seen in more than 70 percents of three part fractures or fracture dislocations, but in less than 30 percents of four part fractures or fracturedislocations. 3. Many complications were developed in almost all cases of four part fractures or fracture-dislocations, but only two complications were founded in three part fractures or fracture-dislocations. 4. The rigid fixation and early mobilization is considered to be a good treatment modality.