Microarray technology is a novel technique to identify the Evaluation of differentially expressed gene.This is very useful for the stastical analysis of DNA chip using different stastical software s.This work is attempted to work on microarray analysis on Alzheimer s disease and identify the differentially expressed gene and their reannotation using R and Biocondcutor.R language is freely available and its latest release is Biocondcutor Software. Here,R language and Biocondcutor software is used for the stastical analysis of hippocampus sample of Alzheimer s disease.The data get normalized using RMA and GCRMA generated different Box plot, Nuse plot, RLE Plot and clustering analysis. Using Biocondcutor different stastical test is a best proof for identify the gene expression level of gene.After annotation identify the gene which were responsible for Alzheimer s disease.The Biocondcutor and R language gives basically identify the main probe which is responsible in that sample for disease and gives the final result which caused the Alzheimer s disease.