Abstarct: Progress of human civilization, population proliferation and application of new technologies have led to various pollutants entering the environment and contamination of water and soil resources. These pollutants can be mentioned to the heavy and toxic mextals such as lead and cadmium, which cause major problems for the health of live organisms. The use of cheap and efficient materials to remove this type of pollutants can be economically useful. In this study with method of adsorption, removal of these toxic mextals from water by three adsorbents, Sepiolite clay, corn biochar, and complex of clay and biochar were investigated. The aim of this study was to compare these three adsorbents for removal of heavy mextals. FTIR and SEM analyses were used to characterize these adsorbents. The effective parameters on the adsorption process include: adsorbents capability by changing the initial concentration of lead and cadmium and presence of adsorbents was examine with contact time changes. The absorption capacity of adsorbents enhanced by increasing concentration in lead from 50 to 1500 mg/l and cadmium from 150 to 800 mg/l, but absorption percentage decreased with increasing concentration. The results showed that the maximum adsorption capacity of lead and cadmium was related to the corn biochar. However, the complex of clay and biochar was more adsorption capacity than the clay. In order to study the adsorption mechanism, the langmuir and freundlich isotherm for each element and adsorbent showed that the adsorption of lead and cadmium by the adsorbents followed by both models but in lead, lanngmuir model and in cadmium, freundlich model showed the best fit with the experimental data by having the highest having the highest coefficient of determination (R2) and the lowest sum of squares error (SSE). The effect of contact time on the adsorption was investigated and it was found that the adsorption efficiency improved by increasing contact time. The fitting of pseudo first order, pseudo second order, elovich and intraparticle diffusions equations models was performed for lead in concentrations of 600, 1000 and 1500 mg/l and for cadmium in concentrations of 150 and 600 mg/l at 30 to 1440 minutes.The elovich model for lead in concentration of 500 mg/l and for cadmium in concentrations of 150 and 600 mg/l and pseudo second order model for concentrations of 1000 and 1500 mg/l showed the best fit to the experimental data. baxsed on the results obtained from the adsorption experiments, it can be stated that corn biochar in comparison to complex of clay and biochar and complex of clay and biochar in comparison with clay has high ability to removing heavy mextals from polluted waters that can be used as a cheap and effective adsorbent for removal of pollutants such as lead and cadmium.