Objective To observe the effects of Yiqi Jiedu prescription drug serum on the apoptosis of human renal cell carcinoma ACHN cells and Notch1 gene in Notch signal pathway. Methods The healthy SD female rats were selected, which were divided into 4 groups, 8 rats in each group: the rats were fed with the normal saline 10 ml·kg-1·d-1 (the blank serum group); the rats were fed with the Yiqi Jiedu prescription decoctum of 50 g·kg-1·d-1 (the high-concentration of Yiqi Jiedu prescription serum group); the rats were fed with the Yiqi Jiedu prescription decoctum of 25 g·kg-1·d-1 (the medium-concentration of Yiqi Jiedu prescription serum group); the rats were fed with the Yiqi Jiedu prescription decoctum of 12.5 g·kg-1·d-1 (the low-concentration medicated of Yiqi Jiedu prescription serum group); then the serum would be extracted 10 days later in each group. ACHN cells at exponential phase were cultured in the above 4 groups. The proliferation of ACHN cells in each group was observed by using CCK-8 method. The apoptosis of ACHN cells was detected by using flow cytometry (FCM). The expression levels of Notch1 mRNA of ACHN cells in each groups were detected by using real time fluorescence quantitative polymerase chain reaction (RT-PCR). Results The inhibition rates of ACHN cells in the high-concentration group, the medium-concentration group, the low-concentration group of Yiqi Jiedu prescription and the blank serum group 24 h later were (12.34±4.25)%, (7.47±1.40)%, (2.52±0.62)%, (1.05±0.31)%, respectively (F=15.04, P < 0.01); after 48 h, the inhibition rates were (24.20±2.41)%, (14.23±1.56)%, (5.08±1.34)%, (1.16±0.14)%, respectively (F=227.36, P < 0.01); after 72 h, the inhibition rates were (32.16±2.45)%, (25.05±3.69)%, (10.29±2.76)%, (1.07±0.71)%, respectively (F=110.51, P < 0.01). The results showed that Yiqi Jiedu prescription drug serum could significantly inhibit the proliferation of ACHN cells in a dose-dependent manner. Besides, the inhibition rate differences at all time points of the high-concentration serum group (F=31.44, P < 0.01), the medium-concentration serum group (F=49.61, P < 0.01) and the low-concentration serum group (F=68.78, P < 0.01) were all statistically significant, and they were in a time-dependent manner. The apoptosis rate of cells in the high-concentration group, the medium-concentration group, the low-concentration group of Yiqi Jiedu prescription and the control serum group was (34.5±1.5)%, (24.4±1.5)% and (13.1±0.5)%, (5.2±0.3)%, respectively, and the differences were statistically significant (F=1 153.36, P < 0.01). The relative expression level of Notch1 mRNA of cells in the high-concentration group, the medium-concentration group, the low-concentration serum group of Yiqi Jiedu prescription and the control serum group was 0.213±0.032, 0.432±0.049, 0.781±0.018, 1.013±0.047, respectively, and the differences were statistically significant (F=270.60, P < 0.01). Conclusion Yiqi Jiedu prescription drug serum can induce apoptosis of ACHN cells, and its mechanism may be related to the down-regulation of the expression level of Notch1 receptors. Key words: Kidney neoplasms; Yiqi Jiedu prescription; Apoptosis; Drug serum; Notch1 receptors