To obtain a cellulose-based yarn fabric having dense fibrils, by treating a cellulose-based yarn fabric with a cellulolytic enzyme and napping the fabric in a wet state.

A cellulose-based yarn fabric is immersed in and treated with a treating solution having 0.5-5.0 g/L concentration of a cellulolytic enzyme composed of exoglucanase or endoglucanase or a cellulase such as cellobiase in a bath ratio of 1:3 to 1:50 for 30-180 minutes. Then the fabric is napped in a wet state increased in fabric water content of ≥100 wt.% in an extended fabric state by a wet sanding machine or the like.