The CBD-encoding region of family 7 cellobiohydrolases gene from the thermophilic fungus Chaetomium thermophilum was inserted into the upstream of the CelB gene from the hyperthermophilic bacterium Thermotoga maritime. The recombinant plasmid pHsh-CBD-CelB was expressed in Escherichia coli JM109. CBD-CelB fusion protein was purified by a simple heat treatment followed by DEAE-Sepharose FF column. The optimal temperature of CBD-CelB fusion protein for CMC activity was 90°C, and the fusion protein had the ability of binding crystalline cellulose. Enzyme activity of CMC and Avicel was increased.