This is a randomized, double-blind, placebo-controlled and multiple dose escalation phase Ib study evaluating the safety, tolerability, pharmacokinetics, pharmacodynamics, and immunogenicity of CM383 in patients with Alzheimer's disease related mild cognitive impairment and mild Alzheimer's disease.

Inclusion Criteria:

• Voluntarily participate and have the subject and their legal guardian jointly sign the Informed Consent Form.
• The age of the subjects is between 50 and 85 years old.
• BMI≥19kg/m2 and ≤32.5 kg/m2, weight ≥45 kg and ≤100 kg at screening or baseline.

Exclusion Criteria:

• Cognitive impairment of subjects due to other medical or neurological factors (other than AD)
• History of stroke or transient ischemic attack, seizures, or other unexplained loss of consciousness within the past year
• With any mental illness that may interfere with the cognitive assessment of the subjects.
• With history of moderate or severe renal dysfunction.
• With Uncontrolled stable hypertension.
• With history of severe trauma or major surgery in the 6 months prior to the screening period, or planned surgery during the study.
• History of malignancy within 5 years prior to screening.