PURPOSE: A method for manufacturing a fish model infected with saprolegnia parasitica is provided to be used for saprolegnia parasitica treatment of temperate fish. CONSTITUTION: A method for manufacturing a fish model infected with saprolegnia parasitica comprises a step of adapting saprolegnia parasitica to a temperate environment, a step of removing scales and epithelial cell using a knife through a scratching technique, a step of putting gold fish without scales and epithelial cell into a water tub, and a step of infecting the gold fish with saprolegnia parasitica.