Abstract: Based on the Z-source inverter, this paper proposed a novel zero-crossing point（ZCP） detection approach of back EMF for Z-source inverter fed sensorless brushless DC motor. By the single channel voltage comparator, the proposed approach compares virtual neutral point voltage with input neutral point voltage during the shoot-through vectors. The proposed approach dedicates zero-vectors and active-vectors to speed regulation, thus gets a wide operation range. The virtual neutral point voltages were analyzed, and the input neutral point voltage was preferred as the reference level of the comparator to reduce errors caused by voltage drops of the power devices. During the shoot-through vectors, both the virtual neutral point voltage and input neutral point voltage do not contain the component of DC supply voltage, so the signal-noise ratio of the detection will not be affected by the voltage attenuation. Moreover, the DC voltage utilization can be improved by the Z-source inverter, and the safety of the drive system can also be improved. The experimental results verify the correctness of the theories and the effectiveness of the proposed approach.