Alzheimer's disease (AD) is the most common form of dementia. One of the research topics is to identify the genes associated with AD through analyzing DNA microarray data by computation. Holding view of vertex coloring of graph theory, in this paper, a new clustering method named vertex coloring clustering (VCC) is presented. VCC is specified for gene clustering, which makes similar gene expression cluster tightly in same class and they share same gene characteristics or function. So, VCC can be also used to identify the genes associated with AD. Using VCC, 27 candidate AD genes are identified in this paper, and 5 genes agree with other men's study.