Abstract: Surficial modification of ground calcium carbonate（GCC） powder was conducted by ball-milling method，using span60 as modifier，ethanol as dispersant.The effects of the rotating speed of ball-milling，ball-milling time，ratio of ball to material，modifier amount on the activation grade，sedimentation volume，oil absorption value，and particle size of the modified samples were investigated by single factor tests.The optimal modification conditions were determined by orthogonal experiment： the rotating speed of ball-milling was 300 r/min，the ball-milling time was 1.5 h，the ratio of ball to material（mass ratio of balls to GCC） was 8∶1，and the modifier amount was 2%（mass fraction）.Results showed that the activation grade of GCC increased evidently，and the sedimentation volume，oil absorption value，and particle size of GCC obviously declined after modification.

Key words: Span60, ground calcium carbonate, surficial modification, ball-milling