This paper presents dynamic analysis of a simply supported porous microbeam made of functionally graded materials subjected to a moving load. Material properties of the porous microbeam change in the thickness direction according to power-law distribution with different porosity models. The governing equations are obtained by Lagrange procedure based on Bernoulli-Euler beam and modified couple stress theories. Then, the resulting equations are solved by Ritz and Newmark average acceleration methods. A detailed parametric study is performed to investigate the effects of porosity coefficient, porosity distribution, material distribution, and length scale parameter on the dynamic responses of functionally graded porous microbeams.