Alkaline sulfite-anthraquinone(AQ) cooking was examined for their effectiveness in delignification of pine (Pinus densiflora S. et Z.) bark. Better delignification was achieved with alkaline sulfite liquor compared to monosulfite liquor, but the degree of delignification was less than 90% indicating need for improvement in cooking method, Remarkable increase in the rate of cooking and delignification was obtained by the simple addition of AQ to the alkaline sulfite cooking, Selectivity of delignification was also improved by the addition of AQ, Consequently, 90% of delignification was achieved with the addition of 0.2% AQ to the alkaline sulfite cooking. The selectivity of delignification was slightly affected by cooking temperature and NaOH concentration during alkaline sulfite-AQ cooking of the bark. The selectivity of delignification was highly affected by the concentration of $Na_2SO_3$, and the optimum concentration of $Na_2SO_3$ for the high delignification was 30% as $Na_2O$.