Abstract: Vinylcyclopropane (VCP), one of the most important cyclic monomers, features a highlystrained three-member ring bearing high strain energy, which leads to feasible 1,5-ring-opening process and other transformations under radical conditions, producing polymers with complex chemical structures including the 2-pentenyl repeat unit. Poly(vinylcyclopropane) (PVCP) often exhibits minimal volume shrinkage even volume expansion and can be used as excellent restorative materials with potential clinical applications. In fact, the free radical polymerization technique facilitates rapid and high-yielding polymerizations of a wealth of VCP monomers with diverse chemical structures, affording corresponding high molecular weight polymers, albeit with uncontrolled mixed repeat units. To selectively access the microstructures of PVCP, the merge of VCP chemistry and modern synthetic strategies, including atom transfer radical polymerization and visible-light photoredox catalysis, have extended the radical ring-opening polymerization (rROP) of VCP to new domains. This review provides a comprehensive overview of the development of the rROP for VCP, focusing on monomer design, strategies to tailor the polymeric structures, and the structure-property relationship. In closing, we offer our perspective on its future development based on the challenges still facing the rROP of VCP.