Abstract: AIM To study the significance of measuring heart rate variability (HRV) in multipleinjury patients. METHODS Changes of HRV in the frequency domain were observed, and norepinephrine（NE） and cortisol（Cor） were measured on the 1st, 3 rd and 7 th day posttrauma in fortysix patients with multipletraumas and in control of 10 health subjects. RESULTS The patients were divided into two groups according to ISS≤16 and >16. Within 24 hour after trauma, LFnm, HFnm and LF/HF increased obviously in both groups. Subsequently, LF, HF and LF/HF of the two groups decreased obviously and were lower remarkably than those of the control group. Compared with those in the ISS≤16 group, LF, HF and LF/HF in the ISS>16 group were remarkably different at every time points after trauma. CONCLUSION Significant changes of HRV occur after trauma, which reflect injuries and imbalance of autonomous nervous function in severe traumatic patients and are closely correlated with the degrees of injury stress.