Abstract: This work conducted the pseudo first order kinetics fitting,pseudo second order kinetics fitting, Elovich kinetics fitting and double constant kinetics fitting for HA adsorption onto Diatomite, and the hermodynamic study by Langmuir equation,Freundlich equation,Temkin equation and Koble-Corrigan equation were also used.The results showed that the adsorption reaction belonged to chemistry adsorption and the pseudo second order kinetic model was more suitable to describe the adsorption reaction than other models.The results showed that the Langmuir equation was more suitable to describe the adsorption reaction than other equations.The adsorption reaction was endothermic and spontaneous reaction because the ΔG0 was negative and theΔH0 was positive.