NOVELTY - The engine (100) has a fin structure (160) placed on a rotation element (140). The rotation element comprises working material e.g. temperature-sensitive magnetic-conducting material. Working fluid flows through the rotation element and forms temperature difference/temperature gradient on the working material. The rotation element is rotated relative to a fixed element (120) along rotating direction (RD1) due to the temperature difference on the working material and due to flowing of the working fluid through the fin structure.    USE - Thermal magnetic/curie engine for power generation applications e.g. ocean temperature difference based power generation applications and hot spring temperature difference based power generation applications.    ADVANTAGE - The rotation element is driven to rotate along the rotating direction by magnetic torque induced from the temperature difference formed by the low-temperature working fluid and the high-temperature working fluid on the working material and by kinetic energy or potential energy from the working fluid flowing through the fin structure and pushing the fin structure so as to enhance efficiency of energy conversion of the engine. The fin structure increases a total contact area between the rotation frame and the working fluid such that the fin structure accelerates rate of heat exchanging in a better manner.    DETAILED DESCRIPTION - The rotation element is a rotation shaft (146) and a rotation frame (142). The working fluid is high-temperature working fluid (Lh) or low-temperature working fluid (Lc) e.g. aqueous liquid, oily liquid, sand or gas.    DESCRIPTION OF DRAWING(S) - The drawing shows a side perspective view of a thermal magnetic engine and main internal structures.    Low-temperature working fluid (Lc)    High-temperature working fluid (Lh)    Rotating direction (RD1)    Thermal magnetic engine (100)    Fixed element (120)    Rotation element (140)    Rotation frame (142)    Rotation shaft (146)    Fin structure (160)