In this study，an encoding monoterpene synthase gene named as CsTPS was isolated from the transcriptome database with GenBank accession number KY829105，and its fulllength cDNA sequence was cloned using RTPCR technique from the tea plant of Tieguanyin cultivar. CsTPS was 2 077 bp in length，containing a 1 752 bp open reading frame（ORF）which encoded 583 amino acid. It was predicted that CsTPS protein containing two aspartic acid enriched motifs, RRx8W and RxR conserved domains，and a chloroplast transit peptide in the Nterminal region. The homology analysis showed that CsTPS was homologous to the monoterpene synthase sequence of various plants，and had 74%，71% and 66% similarity with Daucus carota subsp. Sativus αterpineol synthase，Eleutherococcus trifoliatus limonene synthase and Ricinus communis monoterpene synthase，respectively. Phylogenetic tree analysis showed that CsTPS and several monoterpene synthase of various plants were clustered into TPSb subfamily. Expression analysis showed that CsTPS was upregulated in the processing of White tea withering，Oolong tea zuoqing and Black tea fermentation. In conclusion, CsTPS might be correlated to aroma formation in the tea processing.