Synchronization phenomena in population of interacting elements are the subject of intense research e.orts in physics, chemistry, biology and social science. A successful approach to the problem of synchronization consists of modeling each member of the population as a phase oscillator. In this thesis after introducing the synchronization phenomenon, the stability of frequency synchronized state in networks with di.erent topology is analyzed in Kuramoto model. We considered some solutions for each network. By analyzing the stability of these solutions, it has been shown that according to the sign of coupling strength between oscillators, the solutions are stable or unstable. Then by giving a criterion for the time that system reaches the synchronized state, the e.ect of di.erent frequency distributions on this time was studied for all to all network.