The average molecular weight, the amount of bound phenol of liquefied cellulose and the substitution pattern of bound phenol as well as newly formed residue in the late stage of liquefaction were examined in various liquefaction conditions. The linkage fashion of bound phenol was governed by the liquefaction condition. Phenol extended molecular weight by the reaction with decomposed fragments from cellulose and formed new residue when insufficient amount was charged. On the other hand, phenol played a role of an end-cap reagent when sufficient amount was charged. Bound phenol with o-substitution increased with increasing liquefaction temperature.