In this study, we performed multiplex amplification of exons 18-21 and promoter of EGFR using five pair of primers followed by primer extension to detect base changes or deletions in codons 719, 746-750, 790, 858, and -216 promoter to analyze the mutational frequency in 81 cases of lung cancer, and compared the results to that obtained by direct sequencing. Here, EGFR is linked to lung cancer.