There are many globular clusters in the halo of galaxies, which are composed of about one million stars. They are very closely related to the formation of galaxies. In addition, globular clusters are also one of recent hot topics because they are expected to be a formation site of binary black holes which coalesce due to the gravitational wave emission. However, it is difficult to simulate the evolution of globular clusters, because some binaries are formed in the cluster core. Therefore, we apply P3T (Oshino 2011) based on tree algorithm to reduce the calculation cost, and the GORILLA code (Tanikawa & Fukushige 2009) to solve the orbits of isolated binaries as two-body problem. The results of our simulations show that the orbits of binaries are calculated accurately, and the dynamical evolution could be affected.