Objectives : This study investigated the effect of imbalance of autonomic nerve system on the idiopathic facial palsy by the comparison Heart Rate Variability results of Facial palsy group and healthy control group, and to clarify correlation between House-Brackmann Grade and Heart Rate Variability results. Methods : 119 idiopathic facial palsy patients and 88 health subjects who underwent HRV test were retrospectively reviewed based on medical records. We compared between the HRV results of facial palsy group and that of normal control group, and also compared the HRV results of facial palsy subgroup classified by House-Brackmann Grade. Results 1. All HRV results－Mean Heart Rat(MHRT), Standard Deviation of all the Normal RR intervals(SDNN), Total Power(TP), Very Low Frequency(VLF), Low Frequency(LF), High Frequency(HF), ratio betwween the Low Frequency and High Frequency power(LF/HF ratio) of facial palsy group are decreased compared to that of normal control group, especially SDNN, TP, VLF, LF, LF/HF ratio showed significant difference(p<0.05). 2. HRV results showed no significant correlation in House-Brackmann Grade. Conclusions : This study showed that lower HRV results of facial palsy group than normal control group and suggests that imbalance of autonomic nerve system related with facial palsy. HRV could be a objective tool to reflect condition of idiopathic facial palsy patients.