This paper presents three interaction integrals for calculating dynamic stress-intensity factors (SIFs) for a crack in two-dimensional functionally graded materials of arbitrary geometry. The method involves the finite element discretization, where the material properties are smooth functions of spatial co-ordinates and three interaction integrals for mixed-mode dynamic fracture analysis. These integrals can also be implemented in conjunction with other numerical methods, such as meshless method, boundary element method, and others. Numerical examples involving mixed-mode problems are presented to evaluate the accuracy of dynamics SIFs calculated by the proposed interaction integrals. Comparisons have been made between the dynamic SIFs predicted by the proposed three interaction integrals and available reference solutions in the literature, generated either analytically or by finite element method using various other fracture integrals or analyses. An excellent agreement is obtained between the results of the proposed interaction integrals and the reference solutions. Copyright © 2006 by ASME.