ABSTRACTSince the discovery of superconductivity in MgB2(Tc∼ 39 K), the search for superconductivity in related materials with similar structures or ingredients has never stopped. Although about 100 binary borides have been explored, only a few of them show superconductivity with relatively lowTc. In this work, we report the discovery of superconductivity up to 32 K, which is the highestTcin transition-metal borides, in MoB2under pressure. TheTcof MoB2in the α phase can be well explained by theoretical calculations in the framework of electron-phonon coupling. Furthermore, the coupling between thedelectrons of Mo and the out-of-plane Mo-phonon modes are the main driving force of the 32 K superconductivity of MoB2. Our study sheds light on the exploration of high-Tcsuperconductors in transition metal borides.