Objective:This srudy aims to establish a patient ⁃derived xenograft(PDX)model of NOD background immunodeficient mice for human cancer preclinical and biological research. Methods:NOD ⁃ PrkdcscidIl2rgnull mice were obtained by CRISPR/cas9 technology,and homozygous offspring with stable inheritance were obtained through normal breeding. The proportion of immune cells in peripheral blood of mice was monitored by flow cytometry. Fresh tumor tissues were transplanted and inoculated. The tumor growth status and the morphological characteristics of passaged PDX tumors were observed and recorded. Results:There was no expression of mature T,B and NK cells in peripheral blood of NYG mice. There was almost no rejection to human cells and tissues,and there was no obvious abnormality in histopathological phenotype and immune system. Conclusion:NYG mice and immunodeficient mice were successfully constructed,which provided a new PDX animal model for the basic theory and application of oncology.