In preliminary neutronic assessment was conducted for the design of the DEMO blanket with neutron multiplier and tritium breeder materials packed in a multi-layered area of a blanket container. Beryllium metal and beryllides (Be12W, Be12Ti, Be12V, etc.) are suggested as candidate neutron multiplier materials and material property evaluations of each candidate neutron multiplier materials under neutron irradiation have been carried out. This study estimates the effect of neutron multiplier materials and the effect of the packing configuration on the TBR of the SSTR-based blanket. This work shows that the tritium-breeding ratio (TBR) in a mixed type blanket is about 1.2 times greater than that of separated type blanket. This study shows that TBR of mixed type blanket using Be12Ti or Be12V will be about 1.2 (required TBR is about 1.3), which is 90% of the TBR for a mixed type blanket using Be. It is concluded that Be12Ti and Be12V are the most promising neutron multipliers from the view of the tritium breeding. (C) 2003 Elsevier B.V. All rights reserved.