It is believed that lung cancers are driven by activating or inactivating mutations of multiple oncogenes or tumor suppressor genes, such as EGFR, KRAS, MET, and BRAF, and translocations in the ALK, ROS1, etc. In this study, we comprehensively observed the detection efficacy of tissue- vs. plasma- vs. plasma plus tissue- based NGS of oncodriver mutations as well as compared plasma plus tissue NGS to tissue NGS alone in whole population of 423 lung cancer patients and subpopulations classified according to stages, grades and metastatic status. The gene discussed is KRAS; the disease is lung carcinoma.