Objective To observe the clinical effcacy of DBC AMP-Ca in the treatment of radiation pneumonitis. Methods 30 patients with lung cancer, complicating 2, 3 and 4 degree of radiation pneumonitis were randomly divided into treatment group and control group. Patient in control group were given oxygenaton, glucocorticoid, expectorant, clearing oxygen free radical and antibiotic treatment, while those with more than 3 degree of radiation pneumonitis aminophylline was used. Patients in treatment group received DBC AMP-Ca intravenously based on the treatment of control group. The effects were compared after two weeks. Results The efficiency of DBC AMP-Ca in treatment of radiation pneumonitis is superior to that of control group (P<0.05). Conclusions DBC AMP-Ca is effective for radiation pneumonitis in patients with lung cancer caused by radiotherapy.