The present invention is to provides a content data supply system, a content data supply apparatus and method, a content data reproduction apparatus and method, and a program. The content supply system supplies content data from a content data supply apparatus to a content reproduction apparatus via a network. The content reproduction apparatus includes notification means, content list acquisition means, activation file acquisition means, content data acquisition means, and license data acquisition means. The content data supply apparatus includes customer information management means, content list generation means, activation file generation means, storage means, content data supply means, and license data supply means.