On the basis of the traditional ZSI (Z-source inverter), this paper presents a ESL-${Gamma}$-ZSI, which uses a unique ${Gamma}$-shaped impedance network and an extended SL network for boosting its output voltage in addition to their usual voltage-buck behavior. The inverter can increase the boost factor through adjusting shoot-through duty ratio and increasing the number of inductors. Capacitor voltage stress of ESL-${Gamma}$-ZSI is a constant when 1>D>0, and ESL-${Gamma}$-ZSI has small inductor current stress. The working principle of ESL-${Gamma}$-ZSI and comparison with the classical ZSI and SL- ZSI are analyzed in detail. The power loss comparison between ESL-${Gamma}$-ZSI and Cuk converter is analyzed detailedly. Simulation and experimental results are given to demonstrate the operation features of the inverter.