The utility model provides a taillight plaque mounting structure, includes: set up in the plaque of taillight lamp body (2) rear portion installation side and insert the guide channel, set up in the location strip of taillight plaque (1), the plaque inserts the guide channel can be by fixing a position inserting of strip, the guide insert in taillight lamp body (2) corresponding plaque inserts the guide channel taillight plaque (1), carries out the basic fixed position to the installation of taillight plaque (1), set up in the card foot of taillight lamp body (2) rear portion installation side lower extreme, set up the hook foot that corresponds in taillight plaque (1), the card foot and the taillight plaque (1) of taillight lamp body (2) correspond the installation side lower extreme the cooperation of hook foot, block, prevent that Y that taillight plaque (1) after the basic fixed position takes place relative taillight lamp body (2) rear portion installation side is to, horizontal displacement about promptly. The utility model is suitable for a different figurative car taillight plaques can satisfy under lamps and lanterns space limitation's the condition requirement of convenient and reliable installation plaque.