The present invention relates to a fixing device of an anti-theft signal connector. The fixing device includes a connection seat, a container and a positioning plug. The connection seat is an axial metallic pipe. The connection seat includes a positioning plate which is located in a rear section of the connection seat and integrally formed with the connection seat. The container is axially disposed in a front section of the connection seat. The container has a receiving trough therein facing the positioning plate. The receiving trough is adapted to receive a resistance and a capacitor which are connected in series. The positioning plug is disposed in the front section of the connection seat, so that the container is positioned between the positioning plate and the positioning plug. Thereby, the positioning plate is integrally formed with the connection seat for the resistance and the capacitor received in the container to be steady fixed between the connection seat and the positioning plug. The resistance and the capacitor won't cause signal loss under static electricity.