Abstract: In order to obtain the full-length sequence of NtNRT2.3 and reveal its biological function in Nicotiana tabacum,a predicted nitrate transporter gene sequence in tobacco was gotten with homologous searching. By using RT-PCR technology, a nitrate transporter gene was successfully cloned from the Nicotiana tabacum and named as NtNRT2.3. Its open reading frame was 1455 bp and encoded 484 amino acids. Bioinformatics analysis showed that NtNRT2.3 was highly homologous to the reported NRT2 family genes in plants, such as Arabidopsis thaliana, soybean and rice. And its encoded proteins assumed the common structural characteristics of NRT family. The results of quantitative expression showed that the expression of NtNRT2.3 in roots was higher than that in stalks and leaves, which indicated that NtNRT2.3 gene might play an important role in nitrate absorption of root system.