The utility model relates to an ink box which is detachably installed on an ink-jet printer. An ink supply pipe and a pressurized air pipe which are integrally formed are arranged on the ink-jet printer. The ink box comprises a casing, an ink storage portion, an ink supply portion and a sealing portion. An opening portion is arranged on the casing, and the ink storage portion is arranged in the casing and used for storing ink supplied to the ink-jet printer. The ink supply portion is connected with the ink storage portion and used for delivering ink in the ink storage portion to the printer. The sealing portion is a tubular elastic body which comprises a front end portion matched with the opening portion and a back end portion matched with the ink supply portion in the insertion direction of the ink box. A gap used for communicating the inside of the tubular elastic body and the outside atmosphere is further arranged on the front end side between the ink supply pipe and the inner wall of the sealing portion. The ink box resolves the technical problem that the existing ink box is complex in assembly step and is not easy to plug.