Background: The most common and deadly cancers are lung cancer. There are no symptoms or indicators in its early stages. In study silver nanoparticles of Ginkgo biloba herb were synthesized and prepared solutions of different concentration of this nanoparticles compound, solution of different concentrations of the bilobetein compound which is the main compound in the ginkgo biloba herb. Objective: The purpose of this study was to prepare silver nanoparticles of ginkgo biloba herb and to study the effect of this compound at different concentration as an antifolate, through its reduction of the enzyme DHFR concentration Patient and Methods: This study was divided into three groups as following: thirty samples of blood serum from men and women as a control group with age range 23-45 years, thirty samples of blood serum from men and women of small cell lung cancer patients with age range 45-80 years and finally, thirty samples of blood serum from men and women of adenocarcinoma lung cancer patients with age range 45-80 years. Results:The 4 ppm concentration of the nanoparticles solution gave the best reduction in enzyme concentration in patients of small cell and adenocarcinoma lung cancer compared to control (465.94 ± 238.74 and 700.09 ± 324.59 vs 1680.38 ± 345.51 pg/ml). 8 ppm concentration showed reduction of enzyme concentration in small cell and adenocarcinoma lung cancer compared to control of 586.62 ± 225.57 and 1131.23 ± 415.33 vs 1860.06 ± 163.22 pg/ml. Conclusion: This study concluded the bilobetein and silver nanoparticle of Ginkgo biloba had the ability in preventing growth of cancer cells by reducing the DHFR concentration in sera of small and adenocarcinoma lung cancer patients.