本发明关于式(I)的稠合双环嘧啶化合物。本发明也公开一种抑制极光激酶活性的方法,以及一种用这些化合物治疗癌症的方法。Fused bicyclic pyrimidine compounds of formula (I): wherein R1, R3, R4, X1, X2, Y, Z, A, B, C, D, n, and the two bonds are defined herein. Also disclosed are a method for inhibiting Aurora kinase activity and a method for treating cancer with these compounds.