Synchronization is the adjustment of rhythms of self-sustained periodic oscillatordue to their weak interaction . The existence of plenty of examples showing synchronization in the real world has encouraged lots of scientists and researchers to study the nature of such phenomenon in recent decades. Synchrony in dynamical systems has been the topic of much recent investigations. ecially, for biological systems synchronization phenomena is deserving of importance. The Kuramoto model is one of the simplest and most widely used models describing the synchronization. In this thesis networks constructed from delayed coupled phase oscillators has been investigated using Kuramoto model. These networks are of several types of complex networks by which most of biological systems can be modeled. In most studies in this area time delay in oscillators' couplings has been neglected. That's while time delay in the dynamics of biological systems not only is not negligible, but is so significant as well. We have applied a generalization of the Kuramoto model in which phase coupling among oscillators is considered with time delay, and have attained very interesting results. We have shown in some cases coupling delay causes the system to face an explosive increase or decrease in the level of synchronization. How time delay in coupling can affect the collective behavior of a system strongly depends on its initial conditions (initial phase of oscillators and their intrinsic frequencies).