The breast cancer is dangerous disease in the world . Molecular methods are important and necessary to diagnose breast cancer. Many of the genes with expression change like Bcl-2 gene is specifically, coding an anti-apoptotic protein and and therefore classified as an oncogene. Determine the damage of Bcl- 2 gene as a cause of some types of cancer, such as breast cancer, leukemia, prostate cancer and lung cancer .In this study, we examined Bcl-2 expression levels in (malignant, benign and healthy) tissues of the breast .They were fifty Laboratory samples (18 cancer tumor , 12 benign and 20 marginal (non-cancer) breast tissue that diagnosed based on their information were obtained from their files and records in all patients in this study , to extract the DNA and measure the level of expression of gene under study by molecular technique of ( r –t PCR ). Expression of gene under study is higher levels in malignant group and the fold of expression was 10.00 time higher than the control group and also in the benign group the fold of expression was 2.18 that higher than the control group.The results showed the expressed gene Bcl-2 is significantly higher in the third grade of breast tumor samples with Ct (22.14) of the first grade with CT (25.63) and the second with CT (24.07). According to the results of the study that the use of molecular methods in measuring the expression of Bcl-2 gene may help to diagnose the disease and may be considered that the Bcl2 gene is molecular tool for the early detection of breast cancer