Abstract: An Alternative to conventional converter is a multilevel inverter. The objective is to reduce the harmonics generated by the converter while not increasing the switching losses in the power semiconductor devices. The purpose of multilevel inverter is to generate stair case sinusoidal pulse using DC Source. The Multilevel inverter suitable for high voltage and high power applications. Multilevel inverters are used for industrial drive directly, the THD contents in output voltage of inverters is very significant index as the performance of drive depends very much on the quality of voltage applied to drive. This paper Presents comparison on cascade H-bridge multilevel inverter at different modulation index. THD analysis is carried out using MATLAB simulation.