Piezoelectric energy harvester which is energy converter from mechanical energy to electric energy is expected for next generation wearable energy harvester. The piezoelectric energy harvester based on the human motion can be sustainable energy generating source since human motion based energy converter is independent to the environment condition compared to other energy harvester such as solar and thermoelectric energy harvester. To satisfy the human motion based energy harvester, the piezoelectric fiber type is required flexible and stretchable property. Additionally, because fiber type device has advantages such as highly mechanical degree of freedom and suitability for building block of weaving textile, one dimension fiber piezoelectric generator have been proposed and developed. Here, we developed a flexible piezoelectric yarn type generator using carbon nanotube (CNT) sheets and electrospun (vinylidene fluoride-co-trifluoroethylene) (PVDF-TrFE) mats with silver coated nylon. As rolling the silver coated nylon in electrospun PVDF-TrFE mats as an inner electrode, the two-dimensional piezoelectric PVDF-TrFE mats is easily transformed to one-dimensional yarn. The flexible piezoelectric yarn can be made by forming the coiled structure. Since the flexible piezoelectric yarn could sustain extremely high shear stress generated during coiling procedure. The flexible piezoelectric yarn can be modified as various shapes such as knottable, sewable, and weavable structure. Moreover, since the flexible piezoelectric yarn is stable in twisting, the flexible piezoelectric yarn could be transformed into coiled piezoelectric fiber by twist insertion. The Flexible piezoelectric yarn has potential application as human motion sensors, building blocks of energy harvesting textiles and self-powered biomedical applications.