Certain　learning　the　symptoms　of　earliest　Alzheimer＇s　disease　(AD)　involved　learning,　memory　or　planning　problems.　Currently,　no　medical　tests　are　available　to　diagnose　AD　conclusively　pre-mortem.　However,　a　large　number　of　Kungsholmen　Project　studies　used　cognitive　tasks　(i.e.　visuospatial　tasks,　language　tasks,　etc.)　attempted　to　find　the　preclinical　cognitive　marks　of　AD.　These　studies　convincingly　demonstrate　that　the　cognitive　deficits　of　AD　are　possible　to　detect　during　a　preclinical　period　spans　several　years.　In　addition,　numerous　neuropathological,　electrophysiological　and　neuroimaging　studies　supports　the　hypothesis　that　the　cognitive　deficits　in　AD　is　related　to　a　possible　disconnection　between　cortical　areas.　In　present　article,　we　describe　the　present　and　future　researches　of　early　diagnosis　method　through　cognitive　and　functional　imaging　testing　to　help　with　the　clinical　diagnosis.　©2009　IEEE.