Overstimulation of rubber tree with ethylene can lead to the tapping panel dryness, a physiological disorder leading to the cessation of latex flow. Exogenous ethylene could induce endogenous ethylene biosynthesis causing the release of cyanide, a co-product of ethylene. In plants, cyanide could be detoxifi ed by beta-cyanoalanine synthase (CAS). In this study,full-length cDNA and promoter of HbCAS were cloned and characterized.Its deduced amino acid sequence shared 64.4-89.9% identity with CAS from other plants. The cloned promoter harbored several hormone-responsive elements including salicylic acid (SA) and auxin.Expression level of HbCAS was increased at 16 hours after SA and auxin treatments. The HbCAS expression might be up-regulated for detoxifi cation of cyanide released from endogenous ethylene biosynthesis induced by SA and auxin.