Patients with lung cancer who need thoracic radiotherapy will be enrolled in the trial, then seprated randomly in two group,the KS injection group treated with chemoradiotherapy plus KS injection; the contral group treated with chemoradiotherapy only. After 6 months observation, The rates of incidence and the degree of adverse reactions caused by redioterapy; the completion rate of radiotherapy; clinical Symptoms; Qof and pulmonary function tests etc. will be evaluated.