Objective To observe the effecacy of modified CHOP regimen in the initial treatment of non-Hodgkin' slymphoma (NHL) patients with low Karnofsky score.Methods Twenty initial treatment NHI.patients with low Karnofsky score were randomly allocated into treatment group and control group,respectively treated with modified and standard CHOP regimen.Results Of 13 cases in treatment group,12 pacients'Karnofsky score were over 60.1 was still below 60,overall response (OR) rate was 92.3 % (12/13).while in control group,3 patients' Karnofsky score were over 60,4 were still below 60.OR rate was 100 % (7/7),rate of marrow toxicity was 57.1 % (4/7).There were no significantly difference for OR rates (P =0.4515),but for improving Karnofsky score there were significantly difference (P =0.0149).Conclusion Modified CHOP regimen can improve Karnofsky score of NHL patients with low Karnofsky score,benefical for further treatment and reducing hospitalization cost.