DDS (Displacement Digester System) represents an important trend of pulping technology. DDS kraft pulping of bamboo is studied and effect of cooking conditions (alkali charge, H-factor, sulfidity of white liquor and alkalinity and sulfidity of warm black liquor in warm black liquor pretreatment stage ) on the pulps is investigated in the paper. The results show that: compared to conventional kraft pulping, DDS cooking needs lower alkali charge (16% in conventional and 14.5% in DDS, based on Na2O), the obtained pulp has lower kappa number (kappa number 18 of the conventional pulp and 15 of the DDS pulp). The cooking time can be reduced or even lower kappa number of pulp, or pulp kappa number can be decreased at the same H-factor. The kappa variation (±1.5 of the conventional pulp and ± 0.5 of the DDS pulp). The lower sulfidity (18% in DDS and 25% in conventional) of white liquor is, the lower kappa number of DDS pulp is. In the warm black liquor treatment stage（IC）, alkalinity and sulfidity of the warm black liquor have a great influence on results of DDS cooking. As far as the physical properties of pulp are concerned, the DDS pulp with lower kappa number still has better physical properties.
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