Wearable systems consisted of conformable and lightweight biomedical/strain sensors, power sources, and wireless modules have broad application potentials in human motion monitoring, medical, human-machine interface, safety, and soft-robotics. Our research in this area focuses on combination of conductive nanofibers/polymers and soft scaffold materials (such as elastomers and hydrogels) to design multi-component and multi-functional composite materials. In this talk, I present our recent work on soft, spongy, and conductive materials prepared for wearable human motion monitoring. Three-dimensional (3D) conductive sponge is assembled by freeze-drying of shortened electrospun nanofibers of polyacrylonitrile (PAN), polyimide (PI), and carbon. Highly flexible and compressible conductive sponge is also prepared by one-step dip coating the commercial melamine sponge (MS) in an aqueous dispersion of poly(3,4-ethylenedioxy thiophene):poly(styrenesulfonate) (PEDOT:PSS). Versatile pressure sensors and prototype tactile sensory array based on these pressure sensors are demonstrated.