A method for reducing a production of a build-up slime in a papermaking process is provided. The method includes steps of adding a dispersing agent into the papermaking material to obtain a first mixture, mixing and culturing the first mixture, adding an antagonist into the first mixture to obtain a second mixture, mixing and culturing the second mixture for reducing the production of the slime, and re-adding the antagonist into the mixed and cultured second mixture after a specific time period for further reducing the production of the slime.