Abstract: In order to verify the key role that the decarboxylase probably played in the synthesis pathway of β-phenethyl alcohol in S.cerevisiae, the decarboxylase gene ARO10 was cloned from S.cerevisiae S288C and then inserted into a constitutive expression vector controlled by the promoter of phosphoglyceate kinase gene PGK1, generating a recombinant vector pYES2- Ppgk- ARO10. After pYES2- Ppgk- ARO10 was introduced into S.cerevisiae S288C by the lithium acetate transformation method, the influence of gene ARO10 over-expression on the β- phenethyl alcohol production in the recombinant strain was evaluated. A maximum yield up to 1.0g /L of β-phenethyl alcohol was achieved when the recombinant strain SP10 was incubated for 60h in flask fermentation experiments, which was 16.3% higher than that of the wild strain.The results indicated that ARO10 over-expression significantly increased the β- phenethyl alcohol production in S. cerevisiae S288C, which demonstrated that the decarboxylase played a key role in the biosynthesis of β- phenethyl alcohol. This work established an important foundation for construction of the β-phenethyl alcohol high-producing genetically engineered strains.