A vertical axis wind turbine including: a vertical axis wind mill having a vertical shaft and a generator having a generator rotor shaft, wherein the vertical shaft of the wind mill share the same shaft with the generator rotor shaft. This arrangement simplifies the structure and increases the stability, reliability, and service lifetime of vertical axis wind turbines by making on-site assembly easy and cutting the on-site workload and cost, without undermining the wind resistance capability and safety prompting wider application of vertical axis wind turbines.