Abstract: A protection structure of a sampling tube of a tank truck is provided. A positioning and protecting base is provided around an outer circumference of the sampling tube. The sampling tube includes a sampling output port for connection with a sampling output hose. The positioning and protecting base includes a through hole. The sampling output port extends through the through hole to partly project outside of the positioning and protecting base. With such an arrangement, the stiffness and strength of the entire sampling output port are enhanced for resisting impact and hit, and readiness of connection between the sampling output port and a sampling output hose is not negatively affected to thereby improve usage performance of the sampling tube.