Li-O2 batteries are considered as one of the future candidates for electrochemical power sources due to their high theoretical energy density. As the dominating component affects the performance of Li-O2 batteries, O2-cathode catalyst with high efficiency, low price, facile preparation is important. Herein, polyhedral and porous Mn2O3 rods are fabricated for cathode catalysts in Li-O2 batteries via electrospinning method followed by calcination. The Mn2O3 catalyst possesses a three-dimensional porous structure, which can offer good catalytic activity, expose plenty of active sites and improve the diffusion of electrolyte and O2. When employed as the cathode catalyst, the Li-O2 batteries show enhanced initial discharge capacity of 9701 mA h g−1 at a current density of 200 mA g−1, superior rate capacity and good cycling stability within 160 cycles at the capacity of 500 mA h g−1. These enhanced performances demonstrate a facile method to fabricate Mn2O3 with unique structure as a promising catalytic material for Li-O2 batteries.