Abstract: A transformer with power factor compensation and a DC/AC inverter constructed thereby are presented. The power factor compensation transformer includes a primary winding, a secondary winding, and a power factor compensation capacitor bank, while the secondary winding having a coupling winding and a power factor compensation winding. The primary winding connects to a power grid in parallel, the coupling winding connects to an AC output port of a passive trigger type DC/AC inverter, and the power factor compensation winding serially connects with the power factor compensation capacitor bank. Besides, a triggered switch serially connecting with the power factor compensation winding and power factor compensation capacitor bank is provided when an inductor with air gap links the passive trigger type DC/AC inverter and the coupling winding. Consequently, a function of power factor correction is achieved.