Objective To investigate the potential clinical significance of the change of serum levels of NSE, NO/NOS, IGF-Ⅱbefore and after chemotherapy among Lung cancer patients. Method The serum concentration of NSE, NO/NOS and IGF-Ⅱin 36 lung cancer patients before and after chemotherapy and 35 normal controls were detected by RIA and chemical method. Results The serum concentrations of NSE, NO/NOS and IGF-Ⅱin lung cancer patients before chemotherapy were significant higher than those of normal controls (P< 0.01), while there were no statistical difference between lung cancer patients after three course of chemotherapy treatment and normal controls (P﹥0.05). In contrast, the serum concentrations of NO in lung cancer patients before chemotherapy were significant lower than those of normal controls (P< 0.01), but there was no significant difference between lung cancer patients after three course of chemotherapy treatment and normal controls (P﹥0.05). Conclusion There is an obvious correlation between the changes of serum NSE, NO/NOS and IGF-Ⅱ levels and the progression of lung cancer patients during chemotherapy, which will provide an important clinical significance for treatment of lung cancer patients.