The search for new strains with good productivity of cellulolytic enzymes is always necessary to improve the processes are usually employed. Screening protocols used for these purposes require a low cost and high throughput assay for determination of endoglucanase activity. However, the test proposed by the IUPAC and other microadaptations not meet this requirement. The aim of our work is to obtain an economical and highperformance proposed by IUPAC for determination of endoglucanase activity assay adaptation. For this we reduced the assay volume and investigate the effect of this reduction on endoglucanase activity determination.As a result aminiaturized assay statistically correlated with the assay proposed by IUPAC reduced 10-fold lower scale was obtained. As a result a new economic and high performance adaptation for endoglucanase activity assay based on the IUPAC protocol was obtained.