The acceleration of weight reduction studies in the automotive industry and aerospace industry, the use of lightweight structures in production is increasing. In order for such structures to be used, the strength values should not decrease while the weight is reduced, and parameters such as machinability, recycling and cost should be in the desired properties. Composite materials are among the most preferred materials among light materials due to their high specific strength properties. Thermoplastic matrix composite materials, on the other hand, are the most preferred polymer materials among composite materials due to their recyclable properties. The presence of many superior properties of thermoplastic matrix composite materials provides a wide range of uses. One of these areas of use is working under constant load. Fatigue behavior is an important issue in thermoplastic matrix composite materials operating under continuous load. In this working case, the increasing temperature due to the internal friction at the molecular level in the material causes negative effects on the material and reduces the fatigue life of the material. In order to solve this situation, studies are continuing today to increase thermal conductivity by adding nano-sized additives to the material and to extend the fatigue life thanks to increased thermal conductivity. In this study, it is aimed to give basic information about fatigue behavior in composite materials.