A study to examine the safety and potential effectiveness of human umbilical cord mesenchymal stem cells (hUMSCs) in adults who have suffered spontaneous cerebral hemorrhage in basal ganglia. The hypothesis is that hUMSCs will be safe and can improve neurological function after intracerebral hemorrhage so that improve the prognosis of patients.

Inclusion Criteria:

• Male or female participants between 30 and 75 years of age, diagnosed of spontaneous basal ganglia hemorrhage by imaging (CT, CTA, etc.) with a volume from 10 ml to 60 ml calculated by ABC/2 formula.
• Within 5 days from onset to operation, and no improvement.
• Glasgow Coma Scale (GCS) score of 9 to 15.
• With dysfunction such as hematoma-related motor aphasia, sensory aphasia, hemiplegic limb muscle strength≤grade 3.
• Modified Rankin scale (mRS) score≤1 in past medical history.
• Women of reproductive age have negative pregnancy tests.
• The participants or the legal guardian/representative who are suitable and willing to participate in the clinical trial and can cooperate to complete the follow-ups.

Exclusion Criteria:

• Imaging-based diagnosis of cerebrovascular abnormalities such as ruptured aneurysm, arteriovenous malformation AVM and moyamoya disease as well as hemorrhagic transformation of ischemic infarct and recent recurrence (within 1 year) of cerebral hemorrhage.
• In the sequela stage of cerebral trauma.
• Hematoma involves other structures including but not limited to the thalamus and midbrain or complicated with intraventricular hemorrhage.
• With neurologic impairment before cerebral hemorrhage onset.
• Participants receiving anticoagulant or antiplatelet therapy.
• The disease progresses quickly. Manifestation of cerebral herniation such as bilateral dilated pupil, disappearance of light reflex, and unstable vital signs.
• Active stage of infectious diseases including but not limited to HIV, hepatitis B, and C.
• History of poorly controlled seizures.
• History of severe co-morbidity (including but not limited to hepatic, renal, gastrointestinal, respiratory, cardiovascular, endocrine, immune and/or hematological disorders) which may affect the outcome assessment. Coagulation dysfunction INR >1.4, PTT>37 seconds, thrombocytopenia (PLT<8×10^9/L), serum creatinine exceeded the upper limit of normal by 1.4 times, serum ALT >150U/L, and/or serum total bilirubin >1.6mg/dl.
• Participants with a mechanical heart valve. Biological valves are acceptable.
• Participants with a risk of embolism (including but not limited to a history of left heart thrombus, mitral stenosis with atrial fibrillation, acute pericarditis or subacute bacterial endocarditis). Atrial fibrillation without mitral stenosis is acceptable.
• May be pregnant in the near future or already pregnant.
• Enrolled in this clinical trial or participating in other interventional medical research or clinical trials at the same time.
• Participants difficult to follow up or with poor compliance due to various reasons (including but not limited to geographical and social factors, drug or alcohol abuse).
• Participants or the legal guardian/representative is unable or unwilling to give the written informed consent.
• Vulnerable groups (including but not limited to mental retardation, abuse, inability to fully exercise informed consent).
• Any subject that the researchers think is not suitable for enrollment.

The hUMSCs suspension and placebo solvent have different appearance so only the participants but not the researches can be masked.