With acrylic acid (AA) and poly(ethylene glycol) methyl ether methacrylate (MPEGMA) as comonomers,  ammonium persulfate-sodium hypophosphite acted as the initiation system, monopotassium phosphate as chain transfer agent, polyether scale inhibitor P (AA / MPEGMA) with a long side chain ether group was perpared using water solution co-polymerization method the effects of monomer ratio, amount of initiator, dosage of chain transfer agent, reaction temperature ： reaction time on copolymer calcium carbonate inhibitor efficiency were studied. The results show that when AA and MPEGMA mass ratio is 3∶1, amount of initiator is 4.5% of monomer quality, dosage of chain transfer agent is 11% of monomer quality, the reaction temperature is 82 ℃, polymerization reaction time is 3.5 h, the copolymer calcium carbonate inhibitor efficiency is maximum.