Mitoxantrone Hydrochloride Liposome Injection is a kind of anthraquinone compounds, and its antineoplastic effect has been viewed in preclinical tests. The investigator´s phaseⅠstudy has shown that the drug´s toxicity is manageable and the tolerable does is 20 mg/m2. The purpose of this study is to determine whether Mitoxantrone Hydrochloride Liposome Injection plus Cyclophosphamide,Vincristine and Prednison(CNOP)is safe and effective in the treatment of Diffuse Large B Cell Lymphoma.Patients physical state, symptoms, changes in the size of the tumor, and laboratory findings obtained while on-study will help the research team decide if Mitoxantrone Hydrochloride Liposome Injection plus Cyclophosphamide,Vincristine and Prednison(CNOP)is safe and effective in the treatment of Diffuse Large B Cell Lymphoma.