The full length cDNA of terpene synthase gene (JsTPS) was cloned by combination of RT-PCR and RACE from petals ofJasminum sambac.The results showed that full length cDNA contained 1 491 bp including an 1 884 bp ORF,encoding a 56 989.7 D protein with 496 amino acids whose molecular weight was consistent to that of product of the gene by prokaryotic expression;The result of alignment of amino acid showed that the gene had a homology of 75% to that of olive (Olea europaea),belonging to α-Famesene synthases;Quantities of the gene were detected by real-time PCR in process of opening of flower,the results showed that the expressing level of the gene was minimum at 18:00 when the flowers were not open,then had been increasing until at 22:00 when the expressing level reached to maximum and the flowers was opening.