Objective To investigate the therapeutic effect of polybutylcyanoacrylate nanoparticles loaded with TXNDC5 gene RNA interference chip（TXNDC5 siRNA）on human gastric adenocarcinoma cell implanted tumor bearing model animals. Methods Nano⁃microspheres loaded with TXNDC5 siRNA（TXNDC5 siRNA⁃PBCA⁃ NP）were prepared by emulsion polymerization. The tumor bearing animal model of gastric adenocarcinoma was established by subcutaneous implantation. TXNDC5 siRNA ⁃ PBCA ⁃NP was injected into nude mice bearing trans⁃ planted tumor through caudal vein. At the same time，the blank control group of polybutylcyanoacrylate nanoparticles （PBCA⁃NP），5⁃fluorouracil（5⁃FU）and normal saline groups were established. After treatment，the inhibition of implanted tumor in each group was detected and compared between groups. Results The tumor inhibition rates of the TXNDC5 siRNA⁃PBCA⁃NP treatment group and the 5⁃FU treatment group were（66.98 ± 4.02）% and（64.10 ± 7.55）%，both significantly higher than those of the other control groups（P < 0.05）. At the end of treatment，the aver⁃ age tumor masses of the TXNDC5 siRNA ⁃ PBCA ⁃ NP treatment group and 5 ⁃ FU treatment group were（381.27 ± 24.22）mg and（414.53 ± 29.59）mg，both significantly lower than those of other control groups（P <0.05）. Conclusion The preliminary therapeutic effect on the nude mouse model of gastric cancer shows that TXNDC5 siRNA⁃PBCA⁃NP has a significant therapeutic effect on tumor in vivo. It could have a promising expectation of further study.