Lignin viscous material was prepared from acetosolve lignin by phenolation and heat treatment. The yield of phenolation was about 160% with p-toluene sulfonic acid(2% of acetosolve lignin) as catalyzer. Phenolated lignin has a good spinnability and thermosetting property by $300^{circ}C$ treatment with vaccum. Acetosolve lignin carbon fiber has $20{pm}5$ m diameter and $68.2{pm}10;kg/mm^2$ tensile strength. The yield of carbon fiber based on acetosolve lignin was 31%.