Pharmacogenomics (PGx) as an emerging field, is poised to change the way we practice medicine and deliver health care by customizing drug therapies on the basis of each patient’s genetic makeup. A large volume of PGx data including information on relationships among drugs, genes, and single nucleotide polymorphisms (SNPs) has been accumulated. Normalized and integrated PGx information could facilitate revelation of hidden relationships among drug treatments, genomic variations, and phenotype traits to better support drug discovery and next generation of treatment. In this study, we constructed a normalized cancer based PGx network (CPN) by integrating cancer orientated PGx information from multiple well known PGx resources including the Pharmacogenomics Knowledge Base (PharmGKB), the FDA Pharmacogenomic Biomarkers in Drug Labeling, and the Catalog of Published Genome-Wide Association Studies. The ultimate goal of the CPN is to provide comprehensive cancer specific PGx information to support oncology related research, including cancer based drug discovery – drug repurposing. We have successfully demonstrated the capability of the CPN for drug repurposing by conducting two case studies.