Lung cancer remains the leading cause of cancer-related death throughout the world. Non-small cell lung cancer(NSCLC) is the most deadly form of lung cancer. Patients with non-small cell lung cancer are often found to be unavailable for operation at primary diagnosis. They are typically given conventional chemotherapy. When the tumor progresses during chemotherapy, a change in regimen is considered. The average period of administration differs with the regimen. In this case report, the authors introduce two cases of non-small cell lung cancer patients treated with allergen removed Rhus verniciflua stokes based herbal medicine along with pemetrexed($Alimta^{(R)}$) and erlotinib($Tarceva^{(R)}$). The authors report this case because these molecular-targeted agents were used for longer periods than expected, while improving the performance and other symptoms. Further studies illuminating the synergistic effects through conjunctive treatment with both conventional and Eastern medicine in lung cancer treatment should be performed in the future.