The present invention relates to microorganism control field in process for treatment of pulp and/or water in paper-making process. More specifically, the present invention provides a microorganism control system, which comprises a first component and a second component which are separately provided, the first component comprises a stabilized halogen-containing bactericidal agent (e.g., a stabilized hypochlorite), and the second component comprises an aminosulfonic acid reagent (e.g., aminosulfonic acid). The present invention further provides a method for controlling microorganism in process for treatment of pulp and/or water in papermaking process, which comprises using the microorganism control system of the present invention.
