Project description:MicroRNAs (miRNAs) are a type of small non-coding RNAs, which play important roles in plant growth, development and stress responses. Tea (Camellia sinensis) prepared from tea tree is the oldest and most popular nonalcoholic beverages in the world, and has large economic, medicinal and cultural significance. Nevertheless, there are a few studies on the miRNAs and their functions in Camellia sinensis. We sequenced 9 small RNA libraries and 9 RNA-Seq libraries from roots, leaves and flowers tissues. Through comprehensive computational analyses of 9 small RNA profiles, we identified 200 conserved miRNAs of which 138 have not been reported, and 56 novel miRNAs with 33 have not been reported. Nearly, two thousands genes have significantly different expression levels in tissues. In order to identify targets of miRNAs, we sequenced two degradome profiles from leaves and roots, respectively. Totally, more than 3,000 putative targets of conserved miRNAs were identified in both degradome profiles by using the SeqTar algorithm. These results clearly enhanced our understanding about small RNA guided gene regulations in Camellia sinensis.