Objective To prepare the erythrocyte membrane camouflaged gefitinib(GEF)nanomedi-cine,and to observe its in vivo half-life and blood drug concentration by using the lung cancer bearing nude mouse model and explore its tumor suppression effect and tumor suppression mechanism.Methods The GEF standard curve was established by HPLC.A549 tumor bearing nude mice were constructed and divided into the GEF group,GEF nanoparticles group(GEF-NPs group),erythrocyte camouflaged GEF nanoparticles group(RBC@GEF-NPs group).The plasma drug concentration at different time points was detected by HPLC,the cell cycle was detected by flow cytometry and the tumor cellular apoptosis was detected by TUNEL.Results The tumor volume in the RBC@GEF-NPs group was significantly smaller than that in the GEF group and GEF-NPs group(P＜0.05);the in vivo half-life period in the RBC@GEF-NPs group was sig-nificantly longer than the GEF group and GEF-NPS group(18.90 h vs.2.44 h vs.10.50 h,P＜0.05),and the difference was statistically significant(P＜0.05);the GEF drug concentration in the tumor tissues of the RBC@GEF-NPs group was 48.5 ng/mg,which was 5 times and 2 times of that in the GEF group(10.8 ng/mg)and GEF-NPs group(24.7 ng/mg)respectively(P＜0.05).Compared with the GEF group,the proportion of G0/G1 phase cells in the RBC@GEF-NPs group was increased from 55.5％to 71.35％(P＜0.05)and which in the G2/M stage was decreased from 10.05％to 4.22％(P＜0.05),which in the S stage was decreased from 34.62％to 24.43％(P＜0.05);the cellular apoptosis index in the RBC@GEF-NPs group was significantly higher than that in the GEF group and GEF-NPs group[(23.42±2.47)％vs.(8.34±1.32)％vs.(14.32±2.59)％,P＜0.05],and the differences were statistically significant.Conclusion RBC@GEF-NPs could in-crease the half-life and blood concentration of A549 lung cancer bearing nude mice,block and inhibit the lung cancer growth by promoting tumor cell apoptosis and G1 phase arrest.