Abstract: In the present study, we introduced the H₂O₂-sensitive thiazolidinone moiety at the 4th amino group of gemcitabine (GEM) to synthesize a new target compound named GEM-ZZQ, and then we confirmed its chemical structure by nuclear magnetic resonance spectroscopy. We further confirmed that GEM-ZZQ had a good chemical stability in different pH solutions in vitro and that it could be activated by H₂O₂ to release GEM. Pharmacodynamic studies revealed that the growth inhibition of human normal epithelial cells was weaker by GEM-ZZQ than by GEM treatment and that the inhibition of various lung cancer cell lines by GEM-ZZQ was similar to that of GEM. For the lung cancer cell lines that are resistant to the epidermal growth factor receptor (EGFR)-targeting inhibitor osimertinib, GEM-ZZQ showed less growth inhibition than GEM; however, GEM-ZZQ in combination with cisplatin showed better synergistic effects than GEM in the low-dose groups. In summary, we provided a new anti-cancer compound GEM-ZZQ for treating lung cancer by modifying the GEM structure.