Abstract: A time domain semi-analytical solution to study thermoelastic creep behavior of functionally graded rotating axisymmetric disks with variable thickness is presented. The rate type governing differential equations for the considered structure are derived and analytically solved. To solve these equations, the disk is divided into some virtual sub-domains. General solution of equilibrium equations in each sub-domain can be obtained by imposing the continuity conditions at the interface of the adjacent sub-domains together with global conditions. Finally, solution in terms of rate of stress and strain is obtained. The advantage of present work, is to avoid simplifications and restrictions, which are normally associated with other creep solution techniques in the literature. Results for the stress and strain rates presented due to centrifugal force and thermal loadings for different boundary conditions. Results obtained are verified with those available in the literature for easier cases.