Objective To explore the clinical significance of changes of serum Hcy, IGF- Ⅱ and EGF levels both before and after chemotherapy in patients with lung cancer. Methods Serum Hcy (with ECLIA) , serum IGF- Ⅱ, EGF (with RIA) levels were determined both before and after chemotherapy in 32 patients with lung cancer as well as in 35 normal healthy controls. Result Before chemotherapy, serum Hcy, IGF-Ⅱ and EGF levels were significantly higher in patients than those in controls(P<0.05) , six months after chemotherapy, serum Hcy, IGF- Ⅱ and EGF levels dropped markedly, but remained obviously higher than those in conrrols(P< 0.05), serum Hcy level was positively correlated with serum IGF-Ⅱ, EGF levels(r=0.4984,0.5126, P<0.01). Conclusion The development and progress in patients with lung cancer indicated closely related to the serum Hcy, IGF-Ⅱ and EGF levels.