This paper presents a 4th order CLCL resonant CONVERTER which can be used as a constant current power supply (CCPS) with immittance property. This structure is one of the RESONANCE CONVERTER topologies that has not been studied. This CONVERTER is designed with immittance characteristic with two inductors and two capacitors in the resonant network. A detailed analysis and design process of a 200w CONVERTER as a constant current supply have been provided and simulation results are verified with results of a constructed CONVERTER. In analyzing this CONVERTER, the AC analysis method is used. This CONVERTER with its unique structure, a combination of series and parallel resonant CONVERTER has the advantages of both. As a constant current supply, CLCL resonant CONVERTER has the advantages of rigidity against short circuit, no need to control against load changes, easy operation in parallel mode, low circulating currents and high efficiency about 93%, due to its soft-switching operation. For this CONVERTER, leakage and magnetizing inductance of a transformer can be used as a part of the RESONANCE network and it decreases the CONVERTER size. As a result, the cost of constructing the CONVERTER is reduced. Also, series capacitor eliminates the DC component and prevents the transformer saturation in unbalanced conditions. With fixed-frequency performance, filter design will also be easier. Other structures have only some of these benefits, but this structure has all these. Considering these advantages, the proposed topology can be used in a variety of applications such as magnetic power supplies, capacitor charging power supplies and driver for laser diodes.