In this project, we investigate the di usion coe cient of Brownian particles which are randomly generated on a two dimensional grid. By using the cellular automata techniques we investigate mean square displacement (MSD) and root mean square displacement (RMSD) of particles for xed percent of concentration. We nd the MSD and RMSD of particles at di erent values of concentration. In addition to these, we investigate MSD and RMSD of particles for xed and di erent values of concentration at di erent time steps for a given number of cells