Precision oncology is applying established clinic-pathological indexes with molecular profiling to create diagnostic,prognostic,and therapeutic strategies precisely tailor to each patient's requirements.It includes precision prevention (cancer risk detection and prophylactic intervention),precision diagnosis (early detection and diagnosis,molecular classification),and precision treatment (molecular targeted therapies,predicting and monitoring treatment response and precision surgery based on the combination of visual,cytology,pathologic review,as well as molecular profiling assessments).Understanding of cancer and clinical decision making from the molecular level is necessary in era of precision oncology.Many challenges,including the heterogeneity and dynamic evolution of cancer cells,few understanding about cancer biology,pairing the massive genomic data with inaccurate clinical information,limited sensitive drugs and unexplained resistance,insufficient cancer biomarkers for precision diagnosis and treatment,have to be overcome before it can be clinical routines.