Modern organic synthesis has paid much attention to the chemistry of small carbocycles. Vinylidenecyclopropanes (VDCPs), which have strained cyclopropyl group connected with an allene moiety and yet are thermally stable and reactive substances in organic chemistry, are versatile intermediates in organic synthesis. In this volume, Dr. Lixiong Shao, Dr. Jianmei Lu and Prof. Dr. Min Shi review their investigations on the chemistry of VDCPs, mainly including the preparation, the reactivities upon treatment with Lewis or Brønsted acid, as well as transition metal catalysts and some other miscellaneous analogues. The contributions aroused a renaissance of cationic intermediates in the chemistry of VDCPs.