Abstract: A liquid supply measuring apparatus is disclosed. The provided apparatus is comprised of a housing to be serially installed to a liquid passage in a way that the supplying liquid passes through the housing; a turbine, the turbine is installed inside the housing, wherein the turbine is spin by the passing liquid; a generator, the generator is pivotally or geared joined to the turbine and supplies electrical power according to the turbine's spin; and a controller, capable to calculate the supplied liquid in a way of integrating the supplied electrical power in a time sequence.