Alzheimer’s disease (AD) plays an important role in the medical image processing. It is an irreversible neurodegenerative dementia that often occurs at the age of 65. It is a kind of memory loss that related with thinking and behavior of people’s day to day lives. Therefore, the researchers are taking more efforts to find proper treatment and improve the quality of patient’s life. Besides, this paper represents the review based on segmentation during early detection of AD and MRI classification using ADNI datasets. Further, it concluded with different approaches for better detection of AD.