Abstract: Calcium carbonate particle was modified into hydrophobe with single modifying agent oleic acid，stearic acid， simethicone，and compound modifying agents.The mechanism of calcium carbonate modification was introduced.The influences of sorts and dosages of modifiers on hydrophobic degree were discussed，and the hydrophobic degree was characterized with the activation degree.The structures of modified and unmodified calcium carbonate were characterized by infrared spectrometer，and the results showed that modifiers were introduced onto the surface of calcium carbonate particles. The Zeta potentials of modified and unmodified calcium carbonate were analyzed by zeta potentiometer with different pH， and the results showed the Zeta potentials of the modified calcium carbonate was sharply influenced by pH.The particle sizes of modified and unmodified calcium carbonate were analyzed by laser particle size analyzer，and the results showed the average particle size of the modified calcium carbonate was smaller than that of unmodified one，and its dispersion stability was superior to the unmodified one.The study also provided a method with the change of modifying agent′s types and dosages to adjust hydrophobic degree of the surface of calcium carbonate particles，which had a certain practical significance.

Key words: calcium carbonate, hydrophobicity, characterization