This a MATLAB Simulation for obtaining conduction and switching losses in Three-Phase OHSW(optimized harmonic stepped wafeform) cascaded 9-level inverter.The simulation has been done in several SUBSYSTEMS.The first one produces switching functions based on OHSW.The second one is the 9-level inverter model.the third and fourth obtain load and switching devices currents respectively.The fifth and sixth obtain switching and conduction losses. -This is a MATLAB Simulation for obtaining conduction and switching losses in Three-Phase OHSW(optimized harmonic stepped wafeform) cascaded 9-level inverter.The simulation has been done in several SUBSYSTEMS.The first one produces switching functions based on OHSW.The second one is the 9-level inverter model.the third and fourth obtain load and switching devices currents respectively.The fifth and sixth obtain switching and conduction losses.