Protein kinase C beta (PKCbeta) is a multifunctional serine/threonine protein kinase, which plays an important role in many cell signaling pathways. PKCbeta takes part in multiple physiological processes, including regulation of the cell cycle, differentiation, proliferation, apoptosis and angiogenesis. Increased PKCbeta activity has been observed in many human cancers, such as colon, breast and haematological malignancies. At present, Enzastaurin is mostly studied in preclinical and clinical studies, which is a selective PKCbeta inhibitor. This review focuses on the functional properties of PKCbeta, its role played in tumors and Enzastaurin.