A cDNA encoding a cold-adapted endo-arabinanase (Abnc) was isolated by in vitro cloning from Penicillium chrysogenum 31B. The coding sequence of the abnc gene was 960 bp in length which encodes a 320-amino acid polypeptide. The deduced amino acid sequence of Abnc exhibited 66% and 65% identities to the deduced amino acid sequence of the mesophilic endo-arabinanases of Aspergillus niger and A. aculeatus, respectively, which have been grouped into GH family 43. The presumed catalytic acid and base in enzymes belonging to GH family 43 were conserved as Glu¹⁹⁹ and Asp³⁴ in the deduced amino acid sequence of Abnc. Optimum temperature and thermostability of the recombinant enzyme, which was expressed in Escherichia coli, were similar to that of the P. chrysogenum Abnc. The degrading activity of the recombinant Abnc towards a series of arabinooligosaccharides was higher on more than arabinohexaose. The enzyme did not hydrolyze arabinotriose.