Three-dimensional numerical simulation was performed to show that coarsening and grain growth was affected by particle arrangement in sintering of identical spheres. In the sintering of a row of three spheres the center particle with the coordination number of 2 coarsened, while particles on both sides with coordination number of 1 shrank and disappeared. The particles on both sides disappeared in a shorter time with increasing ratio of grain boundary energy γgb to surface energy γs. A new bond between two particles on both sides was created during sintering of three spheres with bond angle of 70°. This particle rearrangement changed the coordination number, and retarded the coarsening.