For the development of piezoresistive sensor fibers compounds based on thermoplastic elastomer (TPE) matrix and electrical conductive carbon black powder was used. In this paper the fabrication of piezoresistive fibers by using thermoplastic extrusion method will be demonstrated. With the thermoplastic processing route (e.g. melt spinning process) smart functional senor fibers with a diameter of 300 µm where produced. Their dynamic and static electrical conductive properties where investigated by using a cycling mechanical tensile test in combination with conductive measurement. Compounds of three different SEBS type TPEs and compounds with different content of carbon black were used to investigate the influence on the drift and shift of the electrical signal during dynamic and static strain exposure. By changing the SEBS-Block copolymer matrix and by increasing the carbon black content above 45 wt% stable electrical signal with low relaxation behavior can be achieved.