ACladosporium species produced large amounts of cellulase enzyme components when grown in shake-culture with medium containing carboxymethylcellulose. There was significantly less activity when Avicel, filter paper or cotton were used as substrates. KNO3 was better than NH4Cl or urea for the production of cellulase. Tween 80 at 0.1% (w/v) increased the production of cellulase by 1.5 to 4.5-fold. All the cellulase components were optimally active in the assay at pH 5.0 and 60°C.