The effects of exogenous cellulase application on straw decomposition, soil fertility, and plant growth were investigated with nylon bag and pot experiments. Cellulase application promoted straw decomposition, and the decomposition rates of rice and wheat straw increased by 6.3-26.0% and 6.8-28.0%, respectively, in the nylon bag experiments. In pot experiments soil-available N and P contents, soil cellulase activity, and growth of rice seedlings increased. Soil respiration rate and microbial population were unaffected. Seventy U g(-1) was the optimal cellulase concentration for plant growth. The exogenous cellulase persisted in soil for more than 100 days. Although the data show that exogenous cellulase application can enhance soil fertility and plant growth in the short-term due to the acceleration of straw decomposition and has the potential to be an environment-friendly approach to manage straw, cellulase application to soil seems currently not economical. (C) 2009 Elsevier Ltd. All rights reserved.