Patient-derived xenograft models (PDXs) of lung cancer are obtained by directly implanting lung cancer tissue fragments in-to immunocompromised mice. The implanted tumor fragments can be proliferated and passaged in these mice models. The PDXs maintain the tumor microenvironment, histological and pathological characteristics, and tumor biomarkers of the original tumor tis-sues. The PDX also offers an ideal mice model that mimics the human tumor microenvironment. These models have important roles in the pre-clinical evaluation of cancer, the assessment of anti-tumor drug responses, and the analysis of biomarkers. These models also present a new direction for the individualized therapy of lung cancer patients.