Bacterial CpG motifs have attracted considerable interests because of their immunomodulatory activities. Since Bifidobacterium is an important probiotic bacteria with characteristically high G+C content of 60 to 67%, investigation on the immune regulatory activity of CpG oligodeoxynucleotides (ODNs) from Bifidobacterium is warranted. The ODNs containing repeated TCG motifs were designed and synthesized based upon B. longum genomic sequence. Four 21-mer ODNs (ODNBL1~4) and three 25-mer ODNs (CpG ODN1~2, ODNBL5) induced macrophages to secrete cytokines such as IL-6, IL-12p40 and TNF- $alpha$. In particular, ODNBL5 induced macrophages to secret high amount of IL-6 and IL-12 compared with positive control PE2080 which was reported as a strong immune activating CpG ODN. This indicated that the specific functional sequences in the genome of B. longum could activate murine macrophage RAW 264.7 possibly acting as an immunostimulatory modulator for immune response.