As a first aspect, the present invention is, in a state where deterioration has become severely rotation cuff mechanism of the shoulder joint, there is provided a glenoid prosthesis assembly for use in arthroplasty of the shoulder joint, the assembly includes a first shell-shaped component to be secured to the scapula by fixing means, are adapted to be housed in the first component, the second component of small having a connecting surface which connects the upper arm skull, the equipped, the first component since has become a big size for glenoid surface of the scapula, the first component is the shoulder blades of the glenoid, is fixed in at least two places of the acromion and coracoid process, the second component may be, but is cemented in a first component and a predetermined position, to balance the second component to the first component, should give initial adaptability. In another feature, the present invention is to provide a proximal humeral prosthesis of a modular used in shoulder joint molding, according to a difference in the extent of shoulder joint deterioration, the proximal humeral prosthesis but it come to be exchanged between the anatomical and inverted anatomical structure.