Objective:To identify the effect of rat serum containing different concentrations of Buzhong Yiqi decoction（BZYQT） on reverse the chemotherapeutic resistance in A549/DDP cells and on the expression of mTOR.Method: Animals were randomized to prepared the rat serum containing varied does levels of BZYQT（does for 11.34

5.67

2.83 g · kg-1 · d-1）

the A549

A549/DDP were equally divided into six groups in random: the DDP group

BZYQT low does+DDP group

BZYQT middle does+DDP group

BZYQT high does+DDP group

NS+DDP group and the cell control group.Followed by 15%serum of every group and the different concentrations of DDP（10

20

40

80

100

200 μmol · L-1） for 48 h

assayed by MTT to detect the rat serum containing of BZYQT reverse the chemotherapeutic resistance in A549/DDP.The expression of mTOR in cells were evaluated by indirect immunofluorescence

immunocytochemistry technique and Western-blot.Result: The median inhibitory concentration IC50 and resistant multiple of A549/DDP is significant reduction by the serum containing varied does levels of BZYQT（P<0.05）

especially the effect of the middle dose group is the most significant（P<0.01）

the optical density and fluorescence intensity of mTOR were significantly reduced（P<0.01） and the protein expression levels were significantly lower in the cells（P<0.01）.Conclusion: BZYQT appeared to increase the chemotherapeutic sensitivity of A549/DDP cells

showing regression of multiple chemotherapeutic resistance in pulmonary adenocarcinoma by down-regulating expression levels of mTOR.