The growth and metastasis of solid tumors are dependent on angiogenesis.The vascular endothelial growth factor (VEGF) is of particular interest since it is essential for angiogenesis.The development of novel inhibitors of VEGF receptor type 2 (VEGFR-2) is important.Quant. structure-activity relationship (QSAR) studies were performed to understand the structural factors affecting inhibitory potency of 4-aryl-5-cyano-2-aminopyrimidines.Pharmacophore models indicate that the importance of steric and hydrogen bond acceptor groups.The best-fitted pharmacophore-based alignment was used for comparative mol. field anal. (CoMFA) and comparative mol. similarity indexes anal. (CoMSIA).Both CoMFA (q2 = 0.62, r2 = 0.87, and r2predictive = 0.7) and CoMSIA (q2 = 0.54, r2 = 0.86, and r2predictive = 0.61) gave reasonable results.Factors such as steric bulkiness, electrostatic effect, and hydrogen bond acceptor were found to be important for the inhibitory activity.It is suggested that neg. charged, bulky H-bond accepting groups around the piperazine nitrogen would enhance inhibition against VEGFR-2.