Doxorubicin and ifosfamide were the two key drugs that had been widely used for unresectable advanced recurrent soft tissue sarcoma until the recent approval of pazopanib, a molecular targeted drug,for public insurance coverage. The use of pazopanib is increasing worldwide. Pazopanib is a selective oral tyrosine kinase inhibitor that acts on vascular endothelial growth factor receptors (VEGF-R) and inhibits angiogenesis. Recently, it has been shown to exhibit inhibitory effects on platelet-derived growth factor receptors (PDGF-R) and a stem cell factor receptor (c-Kit). Moreover, pazopanib was shown to inhibit directly the proliferation of synovial sarcoma cells and block the PI3K-AKT pathway.