In this study,the cDNA of nitrate reductase (NR) gene in Camellia sinensis was amplified via RACE technology by the EST taken from the transcript library of whole organs in tea plants.And expression levels of NR in different tea cultivars were studied using qRT-PCR technology.The results indicated that the cDNA full-length was 2 927 bp,with 2 652 bp ORF encoding 884 amino acid,the accession number was JX987133 and the sequence was 74% similar to that of tobacco by BlastX.The deduced NR protein is hydrophobic located in the cytoplasm.The expression levels in different cultivars varied greatly and the ratio between the maximum and the minimum reached 22.75.As the fact that nitrate reductase is a key enzyme in the process of nitrogen metabolism,maybe the nitrogen uptake and utilization efficiency differ among these tea cultivars.