The invention relates to medical instruments, in particular to a tracheal catheter capable of directly monitoring the end-tidal carbon dioxide partial pressure of an infant. The tracheal catheter comprises a catheter body, a cuff, a connector, an opening and a thin tube, wherein the cuff is connected to one end of the catheter body, the connector is arranged at the other end of the catheter body, the opening is arranged in a position, between the cuff and the connector and close to the cuff, of the catheter body and connected with the thin tube, and the tail end of the thin tube is connected with an end-tidal carbon dioxide monitor. The tracheal catheter has the advantages that the tracheal catheter is improved to solve the technical problem that due to the fact that the infant is low in body weight, if an existing tail-end sampling device is used, the dilution effect of fresh air flow in the tracheal catheter on carbon dioxide is evident, and the measured end-tidal carbon dioxide is evidently lower than an actual value, the sampling part opening 1 is close to the top end of the tracheal catheter, the inner diameter of the thin tube 2 is small, the fresh air quantity in the thin tube 2 is low, influence of the fresh air flow on the collected breathing gas at the top end of the tracheal catheter is small, the end-tidal carbon dioxide level can be reflected accurately, and the tracheal catheter is evident in use effect.