The microplate colorimetric method has the potential of fast batch-determining activity of soil enzymes. However, so far in China, nothing has been reported on use of this method in measuring activities of lignin-and-cellulose-decomposing enzymes, i.e. polyphenol oxidase (PPO) and β-glucosidase (BG), in the soil and in studying their sensitivity to temperature (EQ₁₀). In this study, based on optimized acidity of the buffer solution, duration of the incubation and buffer/sample ratio of the slurry, the microplate colorimetric method was used to measure activities of the two enzymes in soils under two different farming systems, i.e. consecutive cropping of cotton and alfalfa-switchgrass rotation, and their sensitivity to temperature, and furthermore, its value to the study of soil enzymes was assessed. Results demonstrate that pH 7 of the buffer solution, 2 hours of the incubation and 20:1 of the ratio were the optimal parameters for the test, satisfying both the requirements for batch-analysis and accuracy of the analysis. No significant different was observed between the two cropping systems in soil PPO activity. However, BG activity was much higher in the soil under rotation than under consecutive cropping of cotton. Nevertheless, the two enzymes became more active with rising temperature. The EQ₁₀ values of BG and PPO did not vary much with cultivation systems. It is, thus, concluded that the microplate technique can be used as a routine analytic technique to measure quite rapidly a number of soils and enzymes at the same time in the study of enzymes. Meanwhile, it is necessary to adjust some major parameters properly for use of the microplate method in light of properties of the soil samples.