There are provided (1) a process for producing a contact product, which comprises the step of contacting at least a phthalocyanine complex, a porphyrin complex, or their combination with a surfactant; (2) a catalyst component for addition polymerization, which comprises said contact product; (3) a process for producing a catalyst for addition polymerization, which comprises the step of contacting said catalyst component, a compound of a metal atom of Groups 3 to 12 or the lanthanide series, and an optional organoaluminum compound with one another; and (4) a process for producing an addition polymer, which comprises the step of polymerizing an addition polymerizable monomer in the presence of said catalyst.