Objective To explore gemcitabine’s effect on tumor suppressor candidate 2(EM>Tusc/EM>2), large tumor suppressor2(EM>Lats/EM>2) gene expression in breast cancer of mice, both in mRNA and protein level. Methods Mice models of breast cancer were established and the samples were selected at 0 day, 5 days and 10 days after gemcitabine hydrochloride treatments as well as control. RT-PCR and Western blotting were used to detect the variation of the EM>Tusc /EM>2 and EM>Lats/EM>2 gene expression both for blank control, negative control and test groups. Results The results were similar both in RT-PCR and Western blotting. Compared with blank control, relative amounts of EM>Tusc/EM> 2 and EM>Lats/EM>2 RNA in test group increased around 4-5 and 8 times 10 days after treated with gemcitabine in breast cancer mice respectively (P<0.05). However, no differences were showed with Tusc2 and EM>Lats/EM>2 RNA level 5 days after treated with gemcitabine in breast cancer mice. As to protein expression level, TUSC2 and LATS2 protein relative amounts were raised around 5 and 10 times (P<0.05) compared with blank control. Significant statistical difference was fou