NOVELTY - The hydrogen reforming system comprises a housing, a heat source for generating heat energy, a tube for reforming hydrogen gas, a pipe for supplying a source gas, a unit for opening and closing the tube, a synthesis gas discharge pipe for discharging the reformed gas, a cover member for opening and closing the reforming tube, a unit for coupling the one end of reforming tube to the cover member, and a sealing member for preventing leakage. The heat source and the tube are provided in the housing. The source gas supplying pipe is installed inside the housing.    USE - The system is useful for reforming hydrogen (claimed), which is useful as a fuel for a car.    ADVANTAGE - The system allows reforming of hydrogen in an environmentally friendly manner, and has improved operational efficiency.    DETAILED DESCRIPTION - The hydrogen reforming system comprises a housing, a heat source for generating heat energy, a tube for reforming hydrogen gas, a pipe for supplying a source gas, a unit for opening and closing the tube, a synthesis gas discharge pipe for discharging the reformed gas, a cover member for opening and closing the reforming tube, a unit for coupling the one end of reforming tube to the cover member, and a sealing member for preventing leakage. The heat source and the tube are provided in the housing. The source gas supplying pipe is installed inside the housing. The synthesis gas discharge pipe is fixed to the reforming tube. The coupling unit has a first threaded portion formed on an outer peripheral surface or an inner peripheral surface of the reforming tube, and a second threaded portion formed on an inner peripheral surface or an outer peripheral surface of the cover member. The coupling unit is bent outwardly from the periphery of reforming tube. A flange portion of the coupling unit has fastening holes. The cover member has a through-hole corresponding to the fastening holes. The coupling unit comprises nuts and bolts for fastening the flange portion and cover member. A partition wall is formed in a longitudinal direction in the interior space of the housing. A passage is formed in the source gas supply pipe and is provided with a reforming catalyst for performing reforming reaction.