Prediction of molecular weight (MW) and molecular weight distribution (MWD) of cellulose by means of a rheology-based method is developed. In this method, the effect of cellulose concentration in N-methlymorpholine-N-oxide monohydrate (NMMO center dot H2O) solution on predicting results is discussed. It is shown that there is no significant effect of cellulose concentration on predicting results when the cellulose concentration in NMMO center dot H2O solution is high enough. Meanwhile, the obtained results are compared with those of gel permeation chromatograghy (GPC) method. The comparison shows that the calculated peak MW, polydispersity index (PDI) and MWD curves have the same trends. Consequently, it may be feasible to compare the MW and MWD of cellulose by using the rheology-based method. In addition, the rheology-based method is simple and fast. Therefore it is a useful and easy way to analyze the MW and MWD of cellulose in the fiber industry. POLYM. ENG. SCI., 49:554-558, 2009. (c) 2009 Society of Plastics Engineers