Abstract： Objective： To observe the clinical effect of Dihuang Yinzi combined with cognitive rehabilitation for mild cognitive impairment in Parkinson disease(PD) of yin-yang deficiency type. Methods：A total of 82 cases of PD patients were selected and randomly divided into the control group and the observation group(1∶1)，41 cases in each group. The control group was given levodopa tablets and cognitive rehabilitation，and the observation group was additionally given Dihuang Yinzi based on the treatment of the control group. Both groups were continuously treated for eight weeks. The scores of Unified Parkinson Disease Rating Scale(UPDRS)， Mini- Mental State Examination(MMSE)， and Activity of Daily Living(ADL) were compared between the two groups. Symptom scores of yin- yang deficiency syndrome and clinical effect were compared between the two groups. Results：When compared with those before treatment in the same group，each symptom score of yin-yang deficiency syndrome as well as scores of UPDRS-Ⅰ，UPDRS-Ⅱ，UPDRS-Ⅲ，and ADL in the two groups was decreased after treatment(P＜0.01)，MMSE scores were increased(P＜0.01). After treatment，when compared with those in the control group， each symptom score of yin- yang deficiency syndrome as well as scores of UPDRS- Ⅰ， UPDRS- Ⅱ， UPDRS- Ⅲ， and ADL in the observation group was lower than that in the control group(P＜0.01)， and MMSE score was higher(P＜0.01). The total effective rate was 82.93% in the observation group，higher than that of 58.54% in the control group (P＜0.05). Conclusion：The therapy of Dihuang Yinzi combined with cognitive rehabilitation has a significant curative effect on the treatment of mild cognitive impairment in PD of yin- yang deficiency type. It can improve motor symptoms， cognitive impairment，activities of daily living，and Chinese medicine symptoms.