Natural diatomite was used to adsorb Cd2+ and Pb2+ from wastewater. The adsorption capabilities such as adsorption isotherms and thermodynamics of Cd2+ and Pb2+ by natural diatomite have been investigated. The results demonstrated that the amount of equilibrium adsorption increases with the increase of temperature. The adsorption isotherms of two heavy metal ions accord with the Langmuir equation better. The thermodynamic parameters are showed that the adsorption process is spontaneous and endothermic.