Abstract. To explore the adsorption characteristics of arsenic (III) by Penicillium chrysogenum, the effects of initial pH value, adsorption time, and fungus cell dosage on the adsorption of As 3+ by Penicillium chrysogenum were studied, and the kinetic models were used to explore the mechanism of the adsorption of arsenic(III) by Penicillium chrysogenum. The results showed that the adsorption rate reached the maximum when the pH value was 6. The time for adsorption reached equilibrium was 90 min, and the most suitable amount of fungus was 2g/L. The kinetic experimental data is in good agreement with the pseudo-second-order kinetics model. The adsorption of arsenic by Penicillium chrysogenum includes chemical adsorption.