Abstract: A clamping device for signal wires has a main body having a central through holes. A set of signal wires covered in a common plastic tube is passed through the main body. The end portions of the common plastic tube are cut off for the signal wires to pass through a respective one of through holes of a locating body secured between a front end of the main body and a front ring screwed onto the main body. The main body has a connecting portion that has several connecting plates on rear part for the common tube end portion to be secured in it by screwing a rear ring onto the main body rear part to press the connecting plates inwardly of the main body. The main body further has ornamental annular protrusions on the outer side, and the rear and the front rings have tapered outer sides.