Abstract: Provided is a coupling structure for easy installation and separation of a faucet. The coupling structure includes a connection body which is connected to a water supply pipe at one side and has a coupler at an opposite side. A connection pipe formed in the faucet is fitted to the coupler such that the faucet is coupled to the connection body to allow the faucet to be supplied with water and to discharge the water. A grab ring is formed in the coupler, and an actuation ring is installed in the connection pipe so as to be moved forward and backward. When the actuation ring is moved forward, the actuation ring expands the grab ring to allow the connection pipe to be separated from the coupler. Easy installation of the faucet enhances convenience in construction. Easy separation of the faucet, when necessary, enhances convenience in maintenance.