This paper presents the results obtained using the prehydrolysis treatments of rapeseed stalks depending on regime and the catalyst. The vegetal materials were subjected under different temperature conditions and then characterized for the yield reducing substances. The differences between samples have been established by using FTIR and depend on the successive hydrolytic treatments of dynamic and static regime in the presence of various catalysts. The experimental data show that the hydrolysis reaction induces the modification of cellolignin functionality.