Based on the disparate results of the previously serial studies on intratumoral heterogeneity, we attempted to investigate EGFR mutation status by multi-focal microdissection analysis using different methods (DHPLC vs ARMS), explore the association of the intratumoral heterogeneity with EGFR copy number and imfluence of EGFR mutation contents on response of EGFR-TKI therapy for the patients with locally or advanced NSCLC. The gene discussed is EGFR; the disease is non-small cell lung carcinoma.