Abstract: Numerous cytokines and receptors activate the Janus kinases and signal transducer and activator of transcription signaling, which has been recognized as one of the important pathways in human solid tumors and blood malignancies. JAK-STAT pathway affects the expression and function of a variety of genes that are critical to cell survival, proliferation, angiogenesis, and immune evasion. Recently, targeting JAK-STAT signaling pathway is the hot spot for cancer therapy and a variety of JAK-STAT inhibitors have been identified that induce antitumor cell effects in vitro and in vivo.