An experimental study was carried out to select a suitable complex nutrient medium for growth and As(III) biosorption by an As(III) resistant strain Aspergillus niger X300 .For this purpose different complex nutrient were examined one by one. The recommended complex nutrients (gm%) were corn steep liquir, 20; rice bran extract, 10; paddy soak liquir, 10; wheat bran extract, 15 beef extract, 30, meat extract, 2 0 potato scale extract, 15 and malt extract, 30.