Abstract: Objective: To study the effect of solanum dulcamara water extract on a human lung cancer cell line and to examine its possible mechanism. Methods: The human lung cancer cell line SPC-A-1 was in vitro co-cultured with solanum dulcamara at 4 different concentrations for 24, 48, 72 and 96 h; the MTT assay was used to determine the effect of solanum dulcamara water extract on SPCA-1 cell proliferation; agarose gel electrophoresis (AGE) and flow cytometry were used to detect the apoptosis rate of SPC-A-1 cells exposed to the solanum dulcamara water extract and the change in expression of the apoptosis related gene bcl -2 gene, before and after exposure to the solanum dulcamara. Results: The solanum dulcamara water extract inhibited proliferation of SPC-A-1 cells, and an apoptotic ladder was detected using AGE. There was a very low rate of natural apoptosis (1.37%± 0.52). After exposing the SPC-A-1 cells for 48h to 50.0 mg/ml solanum dulcamara extract, the apoptosis rate was 33.25%±4.39 (P<0.05). The expression of the apoptosis related gene bcl-2 after treatment with 50.0 mg/ml solanum dulcamara extract for 48h (24.41%±2.96) was lower compared to untreated cells (53.53%±4.80) (P<0.001). Conclusion: A specific concentration of solanum dulcamara water extract can inhibit SPC-A-1 cell proliferation and can induce apoptosis of SPC-A-1 cells. The mechanism of action is related to expression of the bcl-2 gene.