An efficient slime control method in a white water circulation line in a paper making process is provided. The present slime control method in a white water circulation line in a paper making process including the steps of: aerating with an oxygen-containing gas either one or both of a white water circulation line and the water feeding line for feeding water into the white water circulation line; and adding a slime control agent to at least one line of the white water circulation line and the water feeding line aerated with the oxygen-containing gas in the aerating step. Preferably, the step of measuring at least one selected from the group of measurement items consisting of the oxidation reduction potential, the sulfite ion concentration and the amount of dissolved oxygen in the white water circulation line is further included. Based on the measurement result obtained in the measurement step, the aeration rate in the aerating step and/or the amount of the slime control agent added in the adding step of the slime control agent may be regulated.
