Hydrolysis of the ammonia borane complex is the optimum procedure to obtain the incorporated hydrogen. In this study, MnO-doped cobalt nanofibers are introduced as effective catalyst for ammonia borane hydrolysis. Compared to cobalt NPs which could release only 1.1mol of hydrogen, the introduced nanofibers revealed better performance as all the equivalent hydrogen (3mol) were obtained at room temperature in a short time. The hydrolysis mechanism was investigated. The nanofibers were synthesized using the electrospinning process. Briefly, electrospun nanofibers composed of poly(vinyl alcohol), cobalt acetate and manganese acetate were vacuously dried and calcined in Ar atmosphere at 850°C.