Abstract: To express laccase cotA gene from Bacillus subtilis in Escherichia coli expression system,cotA gene was cloned from Bacillus subtilis QM11 genome DNA by PCR. Plasmid p ET22 b containing cotA gene was constructed and transferred into competent Escherichia coli BL21(DE3) and the expression of recombinant protein was proved by SDS-PAGE.The gene cotA contained 1542 nucleotides,comprising one open reading frame encoding a polypeptide of 513 amino acids with 58 ku of relative molecular weight and predicted p I value of 5.91 and there was no signal peptide in cotA. The secondary structure of cotA was mainly β-sheet and random coil,β-sheet was 26.71% and random coil was 52.05%. There were twelve-site mutations between the nucleotide sequence from Bacillus subtilis QM11 and cotA(NCBI Gen Bank :GQ184294.1) from Bacillus subtilis,which could result in four amino acid substitution. The molecular weight of cotA gene protein was estimated to be 54 ku by SDS-PAGE.