Abstract: Objective To explore the clinical efficacy of subthalamic nucleus deep brain stimulation in improving core symptoms of patients with Parkinson's Disease (PD).Methods A total of 20 patients with PD who received bilateral subthalamic nucleus deep brain stimulation were selected,their motor symptoms and cognitive capacity on the baseline and after the end of follow up (after postoperative 12 months) were evaluated using self-correlative controlled method,postoperative adverse reactions was observed,and the equivalent dose of daily levodopa before and after operation was compared.Results Scores of Unified Parkinson's Disease Rating Scale part Ⅲ(UPDRS Ⅲ)and each sub-phase scale were evidently lower before and after 12 months of operation in patients with drug administration than those without drug administration (P ＜ 0.05).The above scores were markedly lower after postoperative 12 months than operation before in patients with and without drug administration (P ＜ 0.05),and the improvement rate of each program score after drug administration was prominently higher than operation before (P ＜ 0.05),whereas verbal fluency test (VFT) was notably lower (P ＜ 0.05),and clock drawing test (CDT) was obviously higher after drug administration than operation before (P ＜ 0.05).The equivalent dose of daily levodopa was reduced more significantly after postoperative 1 year than operation before (P ＜ 0.01).None had postoperative complications like intra-cranial hemorrhage,improper position of electrodes,and leakage of cerebrospinal fluid.Conclusion Bilateral subthalamic nucleus deep brain stimulation,with high surgical safety and favorable therapeutic efficacy,can significantly improve PD patients'motor and cognitive function and effectively reduce the dosage of drug.