Abstract: In order to prevent sphalerite particles from agglomeration in leaching solution, and to reduce the loss of organic solvent, surface modification of sphalerite with sodium alginate was investigated. The modified sphalerite particles were characterized by dispersion experiments, determination of adsorption rate of oil, FT-IR spectra and X-ray photoelectron spectra. The results showed that the modified sphalerite particles showed good dispersibility in water.The sedimentation volume was reduced from 0.85 ml•g^-1 to 0.70 ml•g^-1.The adsorption rate of oil reduced from 0.15 ml•g^-1 to 0.07 ml•g^-1.The FT-IR and XPS spectra indicated that some modification regent was coated on the particle surface. The modifier was bonded on the sphalerite particle surface through chemical bond, resulting in the combined stabilization action of electrostatic and steric effect.