Objective:To discuss dosimetric characteristics and acute clinical radiotherapy effects of integrated volume for chest wall target and supraclavicular target with intensity modulated radiation therapy (IMRT) for breast cancer after mastectomy. Methods:Among 146 cases of patients with breast cancer after mastectomy,there were 43 cases of integrated volume IMRT plan(IMRT group) and 103 cases of general 3D-CRT plan(general group). Prescription dose was 50 Gy /25 times/5 weeks,and 90% of target area reached prescription dose. Dosimetry characteristics on the chest wall target,supraclavicular target area and normal organ were compared,while observing and following the partial skin reaction and radiation pneumonitis. Results:Compared with general group the plan of integrated volume with IMRT for the chest wall target area resulted in a better target conformal and uniformity, and in the plan of integrated volume with IMRT for supraclavicular target area,95% prescription dose containing the target volume,conformal and uniformity for the target region were increased obviously, and in the plan of integrated volume with IMRT for breast cancer for the normal organ,the V30 of the ipsilateral lung and V30 of the heart were decreased,while the V5 of the ipsilateral lung and heart were increased. There was no statistical difference of V20 and Dmean of the ipsilateral lung. The occurrence rat of the radiation dermatitis was 37.7%(55/146) and no statistical difference was observed between two groups. None radiation pneumonitis occurred. Conclusion:The plan for integrated volume with IMRT for breast cancer can improve the dose of supraclavicular target significantly by the quantity under the premise for organ at risk,and improve conformal and uniformity of the dose for chest wall target area and supraclavicular target volume.