Abstract: In this paper,palygorskite clay from Linze,Gansu province was selected and modified with different methods such as heat-,acid-,salt-and organic treatments.A gravitational depositional experiment was established to study the effects of these modified methods on properties of suspend stability of palygorskite clay in saturated NaCl solution.The results show that heat-treatment is not benefit for the improvement of suspend property of palygorskite clay.The palygorskite clay modified with 2mol/L HCl has better suspend property than natural and others acid-treated samples.The suspend property of acid-treated palygorskite clay modified with ZnCl₂ was best in all salt-modified samples.The palygorskite clays modified with hexadecyltrimethylammonium bromide possessed better suspend properties than natural and others modified samples.In suspension experiments of all modified samples,the difference between initial pH of suspension and final pH of supernatant was small extensively.It indicates that the interaction of modified palygorskite clay and saturated NaCl solution reach a relative equilibrium in a short time.