A series of Co-N-C catalysts (Co/CNAA-T) were prepared successfully via the pyrolysis of precursor formed by N-acetyl-alanine modified chitosan and cobalt ion at different temperatures. Characterizations were employed to study the effect of pyrolysis temperature on the morphology, structure and composition of the Co-N-C catalysts. It is considered that the Co-Nx site is the catalytic activity center. The prepared Co/CNAA-T catalysts were applied in hydrogenation of methyl phenyl sulfoxide. Meanwhile, the effect of pyrolysis temperature on the catalytic hydrogenation performance of the catalyst was explored. Among them, Co/CNAA-900 shows the best catalytic activity at 140oC and 3MPa hydrogen pressure for 11 hours. The conversion rate reaches 97.2% and the selectivity is more than 99%.