The purpose of this study is to evaluate the efficacy and safety of two fixed dose (1200mg/day, 1600mg/day) of INM-176 (a drug of treating dementia) comparing with donepezil for treatment for patients with Alzheimer type dementia.

Probable Alzheimer type dementia compare INM-176 1200~1600mg/day with Donepezil 5~10mg/day of safety and efficacy to randomization, multicenter, double-blind, double-dummy, parallel Phase III clinical study.

Inclusion Criteria:

1. Male or female, age range : 50 ~ 80 years old
2. Informed consent signed and dated by patient or legal representative
3. Subjects diagnosed with Alzheimer's disease according to DSM-IV criteria
4. Subjects diagnosed with probable Alzheimer's disease according to the National Institute of Neurological and Communicative Disorders and the Alzheimer's Disease and Related Disorders Association (NINCDS-ADRDA) criteria
5. MMSE score 10 to 26
6. CDR(Clinical Dementia Rating) score 1~2 or GDS(Global Deterioration Scale) 3~5 stage
7. Subjects who didn't take any medication for AchEI (donepezil, memantine, galantamin, etc) before treating or can stop medication at least 4 weeks more prior to screening visit
8. Subjects menopause women or her/his spouse consent with contraception during the study period and 90 days after end of study

Exclusion Criteria:

1. Subjects with psychiatric disorders other than Alzheimer's disease, such as schizophrenia, depression, bipolar disorder, etc
2. Subjects diagnosed or accompanied with Dementia due to other Neurodegenerative disorders (AIDS, syphilis, creutzfeldt-jacob disease, Picks Disease, Huntingtons Disease, Parkinsons disease related dementia)
3. Subjects diagnosed with vascular dementia
4. Subjects diagnosed with stroke within last 3 months prior to screening visit
5. Subjects who have medical history of significant hepatic disease in screening visit (2 ULN≤ALT, AST)
6. Subjects who have medical history of significant renal disease in screening visit (1.5mg/dl≤Serum creatinine)
7. Subjects who have difficult with regulating blood glucose level with anti-diabetes drug (8.0%\