This paper presents the implementation of Periodic Boundary Conditions in Finite Difference Time Domain (FDTD) algorithm for the computation of periodic structures. Many electromagnetic problems such as in photonic crystals, scattering and radiation, the periodic scatterers are used. The periodicity of the scatterers is employed to simplify electromagnetic analysis by considering it for an infinite-array. Among other numerical techniques, FDTD provides efficient performance when the number of unknown (or problem size) increases together with covering wide band of frequencies in single simulation. An extensive number of simulated experiments are performed to demonstrate the efficient implementation of PBCs by using FDTD algorithm.