In the guidelines of Advanced Trauma Life Support(ATLS), essential plane roentgenograms (chest AP view, cervical spine lateral view and pelvis AP view) are recommanded when primary survey and resuscitation phase are finished in care of mutiple injured patients. A prospective study was camed on 376 multiple trauma patients who admitted to Wonju Christian Hospital from July, 1995 to October. We analyzed clinical significance of essential X-ray in multiple trauma patients, and classified the patients by their status of mentality. The one is alert group when their Glasgow Coma Scale(GCS) is over 13 point, the other is disoriented mentality group when their GCS are below 12 point. The alert group was redivided by presence of clinical symptoms and/or signs, and clinical significances of essential X-ray were analyzed. Among the 376 patients, 330 patients are alert group that their GCS score is over 13 point and 41 patients are disoriented group who's GCS were below 12 point. The detection rate of abnormality in essential X-ray is higher in disoriented group than alert group(cervical-spine lateral view 13.5% vs 3.0%, cheat AP view ' 35.1% vs 7.6%, pelvis AP view ' 8.1% vs 2.1%). The positive rate in essential X-ray is very low in alert group without clincal symtoms and/or signs(cervical-spine lateral view ' 0.7%, chest AP view 0.4%, pelvis AP view : O%). This study suggests that there are no needs of taking essential X-ray in patients who is alert in mental state and have no clinical symptoms and/or signs.