Abstract: Patient-derived tumor xenograft (PDTX) models are based on the transfer of primary tumor tissue directly from the patient into immunodeficient mice. PDTX models retain many of the key characteristics of the original cancers, including heterogeneity, histological characteristics, molecular diversities, and host microenvironments. These models do not only serve as platforms for co-clinical trials to determine precisely targeted therapies, but can also be applied to the development of biomarkers and action targets for drug responsiveness and personalized drug selection. PDTX models combined with clinical, genomic, and pharmacodynamic data and applied to the individualized treatment of cancer patients could increase the specificity of drug use, improve clinical treatment success, and promote the development of individualized treatment and precise medical regimes. This review summarizes the historical background, influential modeling factors, clinical applications, and limitations of PDTX mouse models.