Using Bi2O3 and MnCl2·4H2O as raw materials,with HCl as solvent,photocatalysts of Mn-BiOCl with different molar ratio of Mn and Bi were prepared by a hydrolysis method.The obtained samples were characterized by XRD,HRTEM,TEM,UV-Vis DRS and SPS.The UV light photocatalytic activity of Mn-BiOCl was evaluated by using methyl orange as model compounds of photocatalytic reaction.The active species in the degradation process of methyl orange were studied.The results show that the Mn content of Mn-BiOCl photocatalysts has an important effect on the catalytic activity.When the molar ratio of Mn and Bi is 0.25%,the as-prepared Mn-BiOCl photocatalyst has the highest catalytic activity toward the degradation of methyl orange.Photocatalytic degradation rate of methyl orange can reach 95.1%.