Abstract: Cells are building blocks of living things. Normal cells multiply when body needs them and die when body doesn’t need them. Cancer appears to occur when the growth of the cell in the body is out of control and cells divide too quickly. In cancer cells display uncontrolled multiplication, invasion and metastasis and caused by abnormalities in genetic material of transformed cells. Samples of microarray experiments performed on homo sapiens of normal and cancerous cells were downloaded from GEO database and these samples were imported to CLC Main Workbench software and expression analysis is performed to identify and rank common differentially expressed Genes in multiple type of cancer, by using technique called DNA Microarray data analysis which is used to find out expression of large number of genes simultaneously and it provides invaluable information on disease pathology, progression, resistance to treatment and therapeutic approaches for cancer. These genes found are useful for drug design as they act as biomarkers and also can be used in further analysis of fundamental signal transduction pathways that lead to carcinomas, since most genes causes cancer which are responsible for causing other cancer e.g. gene causing breast cancer have chances of casing ovarian cancer hence by finding such genes prevention of getting multiple cancer can be done.