A cloth simulation system is provided which comprises a position calculation module calculating relative positions of adjacent vertices among a plurality of vertices on the cloth in the next time step, using the positions of the vertices in the previous time steps; an analysis module establishing an equation of motion of the respective vertices using the relative positions; and an updating module updating the positions of the respective vertices using the equation of motion, whereby the texture and reality of cloth is increased furthermore, a motion of the cloth is calculated in real-time, so that there is no inconvenience to fabricate clothes animation in advance depending upon the number of the motions of to-be-expressed object, thereby considerably reducing the fabricating costs and period.