Abstract: Fibrobacter succinogenes endoglucanase encoded by end-1 is one of the cellulose compound enzymes with capability to degrade cellulose. The codon usage bias of end-1 gene in Fibrobacter succinogenes was characterized by using online software Codon W, CUSP and CHIPS and subsequently compared with that of Escherichia coli, Saccharomyces cerevisiae, Bacillus subtillis and Lactococcus lactis. The results showed that end-1 gene preferred to use codons ending with G/C; a total of 25 biased codons were found（RSCU1）; the codons with stronger bias were GCT, TGC, GAA, GGT, CAC, ATC, CTC, CCG, CGT, TCC and TAC（RSCU ≥2）; there were differences in codon usage bias of end-1 gene between Fibrobacter succinogenes and the 4 hosts genome, and the most obvious differences were found in Lactococcus lactis. The combined data suggest that the codons are required to be optimized when it is heterologously expressed in the 4 hosts at a high level.