Abstract: The technological conditions for surface modification of heavy calcium carbonate particles with poly（butyl acrylate-fumaric acid）［P（BA-FA）］as modifier were investigated by single-factor method.Influences of the dosages of AIBNand TDDM in P（BA-FA） on the modification effect were studied emphatically.The oil absorption value，viscosity，and sedimenta- tion volume of heavy calcium carbonate particles before and after the modification were determined.SEM results showed that，the modifier had a good doping effect on the heavy calcium carbonate，and the oil absorption value，viscosity，and sedimentation volume of the modified particles were all significantly reduced than those that unmodified.The optimum modification conditions were：AIBN amount was 0.047 6 g per 5 g heavy calcium carbonate，and the amount of TDDM was 0.01 mL.Under these conditions，the settlement volume，oil absorption value，and viscosity were 2.921 mL/g，0.359 0 mL/g，and 33 mPa·s，respectively.

Key words: P（BA－FA）, heavy calcium carbonate particles, surface modification, single factor