The co-occurrence of RET fusion with EGFR oncogenic variations was observed in eight patients, and all of the 8 patients have received previous EGFR-TKI treatment. EGFR mutations were including 4 L858R mutations, 4 exon 19 deletions, and 6 T790M mutations. And the partner genes of RET identified by NGS were including TRIM33 (2/8), GPRC6A (1/8), TLN1 (1/8), KIAA1598 (1/8), SPECC1 (1/8), TRIM24 (1/8) and CCDC6 (1/8)....This study extended the knowledge of RET fusion as resistance mechanism to EGFR TKIs in lung cancer.