OBJECTIVE：To investiga te main risk factors for adverse drug reactions （ADR）of skin by intravenous injection of iodine contrast agent. METHODS ：From Jan. 2009 to Apr. 2020，the patients suffering from skin ADR after enhanced CT with iodine contrast agent were collected from our hospital. The basic information ，laboratory test results before using iodine contrast agent and ADR related information were collected through hospital information system （HIS）. The use of iodine contrast agent ，main manifestations of skin ADR and drug combination were analyzed statistically. Taking the sex ，age，body mass index （BMI），the dosage of iodine contrast agent ，length of stay ，laboratory examination ，tumor history ，basic disease ，allergy history ，drinking history as independent variables ，the incidence of skin ADR related to iodine contrast agent was analyzed by single factor analysis ，and the variables with statistically significant were selected for multivariate Logistic stepwise regression analysis. RESULTS ：There were 157 cases of skin ADR ，involving 79 males（50.3％）and 78 females（49.7％）. The age ranged from 19 to 86 years old ，being（52.68± 18.73）years old in average. BMI was 14.6-40.7 kg/m2，being（22.5±3.7） kg/m2. 67 cases（42.68％）were treated with iprodione ，34 cases（21.66％）with iodixanol ，31 cases（19.74％）with iohexol and 25 cases（15.92％）with iopamidol ；the dose of iodine contrast agent were 50-100 mL，being（73.06±13.29）mL in average. There was no significant difference among different dosage of 4 kinds of iodine contrast agents （P≤0.05）. Among 4 kinds of iodine contrast agents ，the incidence of skin ADR induced by iopromide was the highest（0.197％）. The skin ADR related to iodine contrast agent was mainly acute （89.2％），the severity was mild （75.2％），and urticaria（38.9％）was the most common. After symptomatic treatment ，135 cases were cured ，13 cases were improved and 9 cases were not improved. Among the patients with iodine contrast agent related skin ADR ，the incidence of ADR induced by combined use of anti infective drugs was the highest （33.1％）；however，the combined use of anti-tumor drugs was the main cause of severe skin ADR. The length of stay ｛11～20 d[OR＝1.21，95％CI（1.07，1.20），P＝0.042]、21～30 d[OR＝1.39，95％CI（1.12，1.52），P＝0.035]、31～40 d[OR＝1.15，95％CI（1.03，1.37），P＝0.008]、＞40 d[OR＝1.33，95％CI（1.28，1.53），P＝0.003]｝，respitatory and circulatory system tumor history[OR ＝1.51，95％CI（1.35，1.61），P＝0.037]，injection allergy history[OR ＝1.50，95％CI（1.37，1.59），P＝0.005] can significantly increase the incidence of iodine contrast agent related skin ADR. CONCLUSIONS ：The main manifestation of skin ADR related to iodine contrast agent was urticaria. The main risk factors of skin ADR related to iodine contrast agent were length of stay （＞ 10 d），respiratory and circulatory system tumor history and injection allergy history.