Samples (Arundo donax) supplied by Nantong Paper Mill has been studied by alkaline sulfite pulping process. Results indicated that the yield of pulp and the pentosan content in the pulp increased with increment of the ratio of sodium sulfite to the total sodium (all calculated as sodium oxide), but the potassium permanganate value in the pulp changed in a "N" shape. The material, pretreated and unpretreated by hot water, requires at least a total sodium of 16% and 17.5% (calculated as sodium hydroxide) respectly. when the ratios of sodium sulfite to the total sodium are controlled at 82-87%, the yield of pulp exceeds 50%, and the brightness and pentosan contents of pulp are higher and the potassium permanganate value in the pulp are lower than otherwise.