This study will evaluate the safety and efficacy of intracerebral transplantation of human embryonic stem cells-derived neural precursor cells in patients with Parkinson's Disease.

This study is a Phase I/II, open-label, non randomized clinical trial. The study will enroll 50 patients for cell injection, administering a single dose of neural precursor cells by stereotaxic intra-striatal injection.

Inclusion Criteria:

1. Primary Parkinson's disease patients，a history over 5 years，females or males;
2. Cannot effectively control the PD or tolerate the side effects of drugs;
3. Hoehn and Yahr Stage 3 or 4 in the off state at screening
4. Age between 50 and 80 years;
5. Dopamine is effective or once;
6. Sign the informed consent

Exclusion Criteria:

1. Atypical Parkinsonian syndrome or only having tremor syndrome;
2. Having been done pallidotomy, DBS, striatum or extrapyramidal surgery;
3. Subjects are using apomorphine or anticoagulant;
4. Subjects used immunosuppressant or antipsychotic drugs in last 3 months;
5. Subjects used botulinum toxin, phenol, or other drugs for the treatment of dystonia or muscle cramps in last 6 months;
6. During the period of active epilepsy preventing epilepsy with antiepileptic;
7. Coagulant function abnormality or other obviously abnormal laboratory test results;
8. Having skin basal cell carcinoma or cervical cancer and other pre-cancerous lesions;
9. Subject has a history of chronic alcohol or drug abuse ;
10. Pregnancy or lactation;
11. Subjects participated in other clinical trials in recent 3 months;
12. Subject is considered as dementia, a serious mental disorder (depression or mania), and personality or behavioral disorders through cognitive and behavioral test;
13. Cannot cooperate on the research;
14. Severe brain atrophy, or existing brain injury such as cerebral infarction, cerebral vascular malformation or trauma;
15. Severe systemic diseases;
16. Severe dyskinesia or frequent "OFF" or "ON" states
17. Severe infectious diseases (eg HIV, HCV, HBV, syphilis positive)
18. Not suitable to participate in this clinical trial assessed by other physicians