The polymerization of methylmethacrylate (MMA) was carried out by using acrylanilide (AA)-copper (Ⅱ) ion-carbon tetrachloride (AA system) and polyacrylanilide (PAA)-copper (Ⅱ) ion-carbon tetrachloride (PAA system) in distilled water at 85℃. The copolymerization of MMA with styrene (ST) was also carried out at the optimum concentration of each component of the PAA system for the polymerization of MMA. The yields of polymerization of MMA were changed with the variation of the concentration of the components of the AA system and the PAA system, and were considerably high. This result seems to indicate that these systems reveal a catalysis for the polymerization of MMA. The reactivity ratios for the copolymerization of MMA-ST by the PAA system were similar to those for the typical radical copolymerization of MMA-ST. This result suggests that the polymerization of MMA by the PAA system proceeds with radical mechanism.