Carbon-supported copper catalyst was prepared for the first time in one-step with copper nitrate and corn stalk through calcination under different temperatures.Uniformly dispersed nanoparticles were obtained and were identified to be Cu(0) and Cu(Ⅰ) in XRD patterns.Excellent catalytic activity and selectivity were achieved in the N-arylation of pyrazole under ligand and protection gas free conditions.About 90.4％ of product yield was achieved with only 0.5 mol％ of copper catalyst (Cu-C-300),which was considerably more efficient than previous reports.XPS results suggested that the N-arylation of pyrazole activity was closely related to the surface Cu(Ⅰ) species.