Disclosed is a respiration-assisting tube whereby tissue damages in vivo can be prevented and, as a result, inflammatory reactions and infections can be avoided. The respiration-assisting tube is developed based on the finding that adhesion of cells to a respiration-assisting tube can be inhibited by coating the respiration-assisting tube with a polymer containing 2-methacryloyloxyethyl phosphorylcholine (MPC). Also, the respiration-assisting tube is developed based on the finding that, by coating a respiration-assisting tube with a polymer containing MPC, mucosa peeling and tissue damages, which occur after using the respiration-assisting tube, can be prevented and, as a result, inflammatory reactions can be avoided.