Polymer fibers are one of the main substances used for the reinforcement of plastic composites. Their characteristics are very important, especially the thermal properties of the reinforcement materials and matrix polymers. In this work, the thermal properties of polymer fibers were investigated using DSC/DTA/TG. The thermal decomposition kinetic parameters of polypropylene fibers were then evaluated by non-isothermal DSC/DTA/TG techniques. The data from the thermal analysis for the polymer fibers would be a reference fingerprint for thermal analysis.