Abstract: Effect of sodium polyacrylate (PAAS) on the flotation and surface properties of serpentine was studied systematically by means of flotation test, Zeta potential test, Infrared spectral (IR) and SEM-EDS analysis. The flotation results showed that the addition of the depressant sodium polyacrylate could effectively depress the flotation of serpentine, and the recovery of serpentine decreased from 36% to 10% after the addition of 24.7 mg/L sodium polyacrylate. Zeta potential test results showed that sodium polyacrylate could significantly reduce the surface charge of serpentine.Infrared spectral (IR) and SEM-EDS analysis showed that sodium polyacrylate had obvious chemical adsorption on serpentine surface.The mechanism analysis shows that sodium polyacrylate can flocculate serpentine by interacting with the Mg²⁺ on the serpentine surface, and change the dispersion state of serpentine particles, thus effectively depressing the serpentine particles.