Abstract: Objective To investigate the effect of medicated serum of Yiqi Chutan Decoction on the proliferation and apoptosis of human lung carcinoma cells A549. Methods Rats were given Yiqi Chutan Decoction by gavage to get serum containing herb. The proliferation of A549 cells were detected by MTT assay, and the additive amount of serum was determined. The apoptosis of A549 cells was observed by agarose gel electrophoresis and flow cytometry. Results Medicated serum of Yiqi Chutan Decoction could inhibit the activity of A549 cells in a time and concentration dependent manner, with significant difference compared with the blank group (P<0.05). Final concentrations of serum for the experiment were 10% (low dose), 20% (medium dose), and 30% (high dose). Agarose gel electrophoresis results showed obvious apoptotic DNA Ladder bands were found in medium and high dose groups and positive group, while no obvious apoptotic DNA Ladder bands was found in negative group, low or medium dose group. FCM showed the apoptosis of A549 cells in low, medium, high dose groups and positive group were (8.40 ± 1.67)%, (15.80 ± 2.95)%, (27.4 ± 0.96)% and (39.00 ± 1.11)%, which were all higher than that in negative group (P<0.01). Conclusion Medicated serum of Yiqi Chutan Decoction could inhibit the proliferation and induce the apoptosis of A549 cells.