Abstract: Calmodulin (CaM) is a major participant in calcium signaling pathway, involved in multiple physiological processes of plant under cold stress. Using RACE-PCR and RT-PCR, two full-length cDNAs of CsCaM were cloned from tea plant based on the available EST sequences of calmodulin gene. CsCaM1 had 693 bp in length, and CsCaM2 had 841 bp in length. Both of them contained a 450bp open reading frame (ORF) encoded 149 amino acid residues. CsCaMs had four EF-hands, which are CaM gene familes’ characteristic. CsCaM1 and CsCaM2 were submitted to GenBank with accession number KT238971 and KT238972, respectively. The expression profiles of CsCaMs under cold treatment were investigated using qRT-PCR (quantitative real-time PCR). Results indicated that the expressions of CsCaMs were induced gradually with the extension of cold treatment. Under CaCl2 treatment, the expressions of CsCaMs were up-regulated. However, the expressions of CsCaMs were down-regulated under W7 and LaCl3 treatments. Above results demonstrated that CsCaMs might play an important role in cold tolerance of tea plant.