An object of the present invention is to provide a method which can simply suppress fouling in a reactor and, according to the present invention, there is provided a method of polymerizing addition polymerizable monomers using a catalyst formed by bringing (A) a transition metal compound represented by the following general formula [3] or μ-oxo type transition metal compound dimer thereof and (B) an activating agent into contact with one another, the method comprising polymerizing addition polymerizable monomers in a solvent to which a surfactant-containing particle obtained by mixing a particle composed of an inorganic compound or an organic polymer, and at least one surfactant selected from the group consisting of a compound represented by the following general formula [1] and a compound represented by general formula [2] has been added. R1—O—(—R2—O—)m-Q1  [1] R1′C(═O)NR52  [2] L1aM2X1b  [3].