The main focus of this paper is the analysis on the controlling characteristics of self-excited D.C. motor driven by thyristor chopper. The controlling characteristics of short shunt compound motor driven by poly phase multiple thyristor chopper is better than that of driven by single phase thyristor chopper. And we got the following conclusions. A. Motor current capacity could be increased by the multiplicity n increase. B. Speed-torque characteristics is linear and adquate for constant Horsepower motor. C. Maximum current Riple ratio is proportional to almost inverse m$^{2}$. Also here shows the stable conditions and semiconducterlize datas for controlling the self-excited D.C. motor driven by thyristor chopper.