Objective:To study the effect of arsenic trioxide(As_2O_3)combined with ginsenosides Rg3 on inhibiting the NCI-H1299 lung cancer cells and subsistence in nude mice bearing hepatoma.Methods:MTT method was used to measure the inhibition effect of(As_2O_3)combined Rg3 on NC1-H1299 cells,and the proliferation inhibiting effect was observed via establishing the transplanted tumor model in vitro.A total of 40 tumor-bearing nude mice were randomly divided into normal saline group,(As_2O_3),Rg3 and As_2O_3+Rg3 group.Transplantation tumor model of lung cancer in nude mice was constructed,followed by injection of certain concentrations of normal saline,As_2O_3,ginseng saponin Rg3 and As_2O_3+Rg3 every day.The survival duration and the tumors size of the mice were recorded and the Kaplan-Meier curve was made;microscopic observation of apoptosis of tumor cells in vivo was done using TUNEL staining.Results:After 72 h of injection.inhibition rate of tumor cell in normal saline group,As_2O_3 group.Rg3 group and As_2O_3+Rg3 group was(5.66±0.31)%,(65.58±4.75)%,(44.69±3.32)%and(82.67±5.43)%,respectively.Inhibition rate of tumor cell in As_2O_3 group.Rg3 groap and As_2O_3+Rg3 group was significantly higher than that of normal saline group(P<0.01);inhibition rate of tumor cells of As_2O_3+Rg3 group was significantly higher than that of the two groups given As_2O_3 or Rg3 alone(P<0.01).The tumor volume of As_2O_3 group,Rg3 group and As_2O_3+Rg3 group shrank to(65.38±3.25)%,(77.68±3.43)%and(42.65±3.55)%of the original,tumor volume of saline group was 1.21 times of the original size(P<0.01);Median survival of saline group,Rg3 group,As_2O_3 group were significantly shorter than that of As_2O_3+Rg3 group(P<0.01);co-ordinated intervention ability of As_2O_3+Rg3 on NCI-H1299 cell was significantly higher than that of As_2O_3 or Rg3,separately.Conclusions:As_2O_3 combined with Rg3 can significantly inhibit prolifaration of NCI-H1299 cells in lung cancer,prolong survival fo tumor-bearing nude mice,and promote tumor cell apoptosis,and have significant effect on lung cancer treatment. Objective: To study the effect of arsenic trioxide (As_2O_3) combined with ginsenosides Rg3 on inhibiting the NCI-H1299 lung cancer cells and subsistence in nude mice bearing hepatoma. Methods: MTT method was used to measure the inhibition effect of (As_2O_3) combined Rg3 on NC1-H1299 cells, and the proliferation inhibiting effect was observed by establishing the transplanted tumor model in vitro. A total of 40 tumor-bearing nude mice were randomly divided into normal saline group, (As 2 O 3), Rg 3 and As 2 O 3 + Rg 3 group. Transplantation tumor model of lung cancer in nude mice was constructed, followed by injection of certain concentrations of normal saline, As 2 O 3, ginseng saponin Rg 3 and As 2 O 3 + Rg 3 every day. The survival duration and the tumors size of the mice were recorded and the Kaplan- Meier curve was made; microscopic observation of apoptosis of tumor cells in vivo was done using TUNEL staining. Results: After 72 h of injection. Inhibition rate of tumor cell in normal saline group, As 2 O 3 group. Rg (5.66 ± 0.31)%, (65.58 ± 4.75)%, (44.69 ± 3.32)% and (82.67 ± 5.43)%, respectively.Inhibition rate of tumor cell in As_2O_3 group.Rg3 groap and The inhibition rate of tumor cells of As 2 O 3 + Rg 3 group was significantly higher than that of the two groups given As 2 O 3 or Rg 3 alone (P <0.01). The tumor volume of As 2 O 3 group, Rg 3 group and As 2 O 3 + Rg 3 group shrank to (65.38 ± 3.25)%, (77.68 ± 3.43)% and (42.65 ± 3.55)% of the original, tumor volume of saline group was 1.21 times of the original (P <0.01); The co-ordinated intervention ability of As 2 O 3 + Rg 3 on NCI-H 1299 cell was significantly shorter than that of As 2 O 3 + Rg 3 group higher than that of As_2O_3 or Rg3, separately.Conclusions: As_2O_3 combined with Rg3 can significantly inhibit prolifaration of NCI-H1299 cells in lung cancer, prolong survival fo tumor-bearing nude mice, and promote tumor cell apoptosis, and have significant effect on lung cancer treatment.