Abstract: A strain of iungus (Penicilium sp.) capable of high uptake for dyes was isolated from air to remove the cationic dye malachite green from aqueous solution and the effect of fungal biosorption on dye removal was investigated experimentally, including dye structures, pretreatment methods and initial pH values of the solution. The results showed that the adsorption quantity of untreated and NaHCO3-treated fungal mycelia as biosorbent are 29.3 and 35.3 mg/g if the concentration of the dye malachite green is 50 mg/L, respectively, and the latter has best effect. In the biosorption process the pH value plays an important role, and the maximum adsorbability can be obtained at pH value 5. The Langmuir and Freundlich models are able to describe the biosorption equilibrium of malachite green with the NaHCO3-treated fungal mycelia. The maximum uptake is 555.6 mg/g dry biomass. The dye biosorption process by fungal mycelia follows the pseudo second-order kinetics equation.