A content distribution system distributes at least either one of a first content and a second content to a terminal (3) through a network from a distribution server (1) which stores a compression coded bit stream of the first content and a compression coded bit stream of the second content. The content distribution system has a conversion device (2) which, when a syntax indicating an order to be satisfied by the bit stream of the content distributed from said distribution server (1) to said terminal does not match a syntax of decoding information preliminarily notified to the terminal, converts the syntax of the content distributed to the terminal to match the syntax of the decoding information before distributing the same to the terminal (3). The conversion device (2) performs through processing on the content without converting the syntax thereof when the syntaxes match each other, whereas when the syntaxes do not match, the conversion device converts the syntax of the content before distributing the same to the terminal.