The nanosystem composed of only as few as seven endohedral fullerene K+@C60 molecules was simulated using the MD method. The interaction was taken to be the full site-site pairwise additive Lennard-Jones (LJ) potential, which generates both translational and anisotropic rotational motions of each endohedral fullerene. The atomically detailed MD simulations allow the dynamics of the motion of K+@C60 molecule inside the cluster to be analysed. The radial distribution function, the mean square displacement, the translational velocity correlation functions and the Lindemann index of endohedral fullerene have been calculated for several energies of the nanosystem. The solid/liquid phase transition and the existence of the liquid phase in the endohedral potassium ion fullerene cluster was found.