The invention relates to a kind of animal agentia and the preparative of it, which has something to do with the animal drug technology. The material of the agentia is dandelion, which can relieve the fever, deintoxicate, lessen swelling and eliminate stagnation. The making procedures go as follows: remove the impurities of dandelion and clean it thoroughly; cut it into several sections and crush the dandelion; extract the smashed dandelion; mix the filtered solutions together; dry the solution into powder and smash it into refined dandelion powder. The extracting procedure includes two steps mainly, the first step is extracting the material in solution at ph2-5(adjusted by 10% acid solution) for 2 hours; the second step is extracting the material in solution at ph8-9(adjusted by 10% acid solution) for 8-9 hours. The agentia can treat the loimia of livestocks and poultries very effectively. The processing technology adopts the water-extracting method, besides it adopts acids before alkaline during extracting so that it can retain the effective ingredient of the drug. The effective ingredients of the refined powder have overcome the absorption problem of dandelion, so that the agentia can increase the economic benefits and decrease the producing cost of the animal agentia.