The present invention relates to a sterilization system for a water purifier, i.e., a system which can sterilize, using hot water and steam, the interiors of a filter, a water tank, a cooling tank, a hot water tank, lines connected to each unit, and a water nozzle of the water purifier, which are vulnerable to bacteria. The system of the present invention effectively sterilizes the water purifier to enable users to use a highly clean water purifier.
