Aim To explore the key genes of osimertinib aequired resistanee in non-small eell lung eaneer eells based on transcriptomics, anrl to analyze the significance in osimertinib resistant eells. Methods Hu man lung cancer HI975 cells and osimertinib resistant HI 975/OR cells were cultured in vitro. The effect of osimertinib and ferroptosis inducers on cell viability was measured by CCK-8 assay. The difference in gene expression was measured by transcriptomics. Hie expression levels of ferroptosis-related proteins were measured by Western blot. Results Osimertinib j eould inhibit the proliferation of HI975 eells and HI 975/OR eells in different concentrations, and HI975 cells were more sensitive. Transcriptomics analysis revealed remarkable differences in gene expression levels between HI975 and H1975/OR cells, among which the ferroptosis pathway was most significant. Western blot assay validated that different degrees of change existed in the expression levels of ferroptosis-re- lated proteins in HLF-1 , H1975 and H1975/OR eells. After the treatment of ferroptosis inducers RSL3 and Erastin, H1975/OR cells showed higher sensitivity, while little significance was observed on HI975 cells. Conclusions There were significant differences between HI975 lung cancer cells and osimertinib resist-ant H1975/OR cells on the gene expression levels, and the ferroptosis pathway plays an important role in acquired resistance to osimertinib.