This study evaluates the effects of "computerized cognitive training" and "cognitive training plus exercise training" on different cognitive domains in mild cognitive impairment (MCI) patients. Patients will be randomized into the computerized training group, cognitive training plus exercise training group and the control group.

Mild cognitive impairment (MCI) is an early stage of Alzheimer Disease (AD). Increasing evidence has indicated that cognitive trainings improve cognition functions of MCI patients in multiple cognitive domains, making it a promising therapy for MCI. However, the effect of long-time training has not been widely explored. It is also necessary to evaluate the extent of its function in reducing the conversion rate from MCI to AD.

Inclusion Criteria:

• Male or female, aged 50-85;
• MCI diagnosed according to the National Institute on Aging-Alzheimer's Association (NIA-AA) workgroups[1];
• 24≤Mini-Mental State Examination (MMSE) ≤28；
• The Hamilton Depression Scale/17-item (HAMD) score ≤10;
• Not on medication for dementia;
• MRI T2 weighted image (T2WI) scan: aged ≤70 , Fazeca scale for White Matter lesions rating level≤1; >70 years, white matter damage rating scale ≤2. The number of lacunar infarcts larger than 2 cm in diameter ≤2. No infarcts in hypothalamus, entorhinal cortex, para-hypothalamus, cortical and subcortical cavity infarction near gray matter nuclei. The medial temporal lobe atrophy (MTA) score: Grade II or above.
• Accompanied by reliable caregivers (at least intensive contact of 4 days every week and 2 hours every day) who are expected to participate in the follow-up visits and provide useful information for scores of scales like ADCS-ADL;
• Education level: primary school (grade 6) or above.
• Expected good compliance with the therapy and follow-up. Each patient gives a written informed consent, and the study has been approved by Ruijin Hospital's ethical committees.

Exclusion Criteria:

• Cognitive decline caused by other diseases (cerebrovascular disease, central nervous system infections, Parkinson's disease, metabolic encephalopathy, intracranial space-occupying lesions, deficiency of folic acid/vitamin B12 and hypothyroidism);
• Medical history of other neurological disorders (including stroke, Neuromyelitis optica, Parkinson's disease, epilepsy, etc.);
• Psychiatric disorders defined by (Diagnostic and Statistical Manual of Mental Disorders) DSM-IV criteria;
• Unstable or severe disease of heart, lung, liver, kidney or hematopoietic system;
• History of alcohol or drug abuse;
• Participation in other clinical trial less than 30 days before the screening of this study;
• Inability to complete the study.