Supercontraction fiber with shrinkage ratio as high as eight times is processed from simple polymer blending and melt spinning. Specifically, polycaprolactone and ethylene-octene block copolymer blends are made and then processed into fibers with a two-step sequence of melt extrusion and room-temperature drawing. The morphological properties, mechanical properties, rheological behavior, thermal properties, and shrinking ability of the blend fiber are characterized. The scanning electron microscope images of the blends indicate two types of structure: cocontinuous structure and matrix-droplet structure. Fiber made from the cocontinuous blend has the supercontraction ability, while fiber from the matrix-droplet blend does not. Additional hot drawing of the fiber at 50 degrees C is found to be helpful for improving the mechanical properties, shrinking ratio, and shrinking stress. Cyclic tensile testing was also conducted and the results show that the supercontraction fiber may be used repeatedly for multiple times. POLYM. ENG. SCI., 2020. (c) 2020 Society of Plastics Engineers