By constructing a genomic library, an endoglucanase gene (cel9P) was cloned from Paenibacillus sp. BME-14 which was isolated from the sea. It had an open-reading frame of 1,629 bp, encoding a peptide of 542-amino acid residue with a calculated molecular mass of 60 kDa. The enzyme showed the highest amino acid identity of 52% with other known endoglucanases and had a C-terminal catalytic domain belonging to the glycosyl hydrolases family 9. The optimum pH and temperature for enzymatic activity was pH 6.5 and 35 degrees C. The metal ions of Ca(2+), Mg(2+), and Mn(2+) had a positive effect on the activity while Hg(2+), Cu(2+), and EDTA had a negative effect. Notably, Cel9P had 65% of the maximal activity at 5 degrees C. Based on the special characteristic of Cel9P, it had a potential significance for study of cold-active mechanism and industry applications.