Due to increasing high operating frequency of the forward converters and unnegligible parasitic capacitance of switching devices, some traditional circuit models are no longer applicable for performance evaluation. In this paper, forward converters are evaluated by two magnetic recovery circuit models based on the phase plane analysis method which are different from the traditional model. One is the LC series resonance magnetic recovery circuit model and the other one is the magnetic recovery winding circuit model. Through the phase plane analysis method, the operating characteristics of forward converters can be fully analyzed which can be used to predict the operating performances. Proper selection of these characteristics and parameters for forward converter designs often play a crucial role in determining the success or failure of the design and the reliability and safety of the product. Combined the expected voltage stress and loss of switching devices, optimal operating states of forward converters can be achieved.