Abstarct: Transformers are the bulkiest blocks in power electronic circuits, having significant role in efficiency and performance of the system. Leakage inductance determination have momentous impact on power electronic converters. In resonance converters or in circuits which integrating the filter inductance and leakage inductance in order to eliminate some harmonics of output waveform is needed, leakage inductance determination is required. In this research a design method of medium frequency transformer which is used in inverter has investigated. The leakage inductance analytical formulas has stated for some winding configurations and a transformer design procedure in order to present specific leakage inductance has proposed. The configurations and their restrictions has compared and investigated by finite element method which has carry out by Magnet software. Finally the proposed method has implemented on two different configuration, by construction shell-type and core-type prototype transformers to validate and comparing results.