Objective To investigate the application of iohexol in enhanced CT scanning. Methods The total of 623 patients taking iohexol for enhanced CT scanning were sampled to record relevant data for reference. According to evaluation standards for rational use of contrast media,the risk factors,selection of contrast media,medication time,usage and dosage,and drug combination were analyzed statistically. Results Among 623 patients used iohexo for enhanced CT scanning,302 patients had the risk factors of adverse reaction(the incidence rate as 48.48%) and 115 patients received psychological intervention(the incidence rate as 18.46%).And 206 patients had been given with the reasonable fluid therapy before and after angiography(the incidence rate as 33.07%),there were only 124 patients who performed the renal function and urine routine examination 48-72 h before and after angiography(the incidence rate as 19.90%).And 33 patients occured allergic reaction with the incidence rate as 5.30%. Conclusion There existed irrational phenomenon in application of diodone in enhanced CT scanning.It is necessary to further standardize the clinical application of diodone and make complete measures for rational use of diodone.