Abstract: The effect of sodium hexametaphosphate (SHMP) on serpentine flotation behavior and surface property were studied by flotation tests, zeta potential tests and DLVO theory. The flotation tests results showed that floatability of serpentine was poor and sodium hexametaphosphate had a good inhibition effect on serpentine. It was analysed that sodium hexametaphosphate can react with Mg2 and adsorbed on the surface of serpentine, which leaded to inhibition of serpentine. Can be seen from results of DLVO theory, aggregation and dispersion of serpentine particles can be changed by sodium hexametaphosphate.