Objective: To investigate the expression of FTO (fat mass and obesity associated) gene in breast cancer tissue and the influence of neoadjuvant chemotherapy on its expression. Methods: The FTO mRNA expressions in 28 cases of hyperplastic breast tissues, 24 cases of breast cancer tissues and 10 pairs of breast cancer tissues taken before and after neoadjuvant chemotherapy were determined by RT-PCR method. In addition, the relations of the expression level of FTO mRNA with the clinicopathologic parameters of the breast cancer patients were analyzed. Results: FTO mRNA was expressed in both hyperplastic breast tissue and breast cancer tissue, but its expression level in breast cancer tissues was significantly higher than that in hyperplastic breast tissue (P<0.05). The expression level of FTO mRNA in breast cancer tissue after neoadjuvant chemotherapy was lower than that before neoadjuvant chemotherapy (P<0.05). The expression level of FTO mRNA was associated with lymphatic metastasis, which was higher in the patients with lymphatic metastasis than that in patients without lymph node involvement (P<0.05), while it was not relevant to the status of ER and PR receptors, CerbB-2 gene or the degree of obesity of the patients (all P>0.05). Conclusion: FTO expression is increased in breast cancer tissues, which may probably be associated with the occurrence and development of breast cancer; FTO mRNA expression in breast cancer tissues can be reduced by neoadjuvant chemotherapy.