Two hundreds fifty seven cases of normal mammogram were analysis for classification of types of breasts. Ranging from 20 to 79 years of age, mean age was 45 years. Two projections, craniocaudal & mediolateral, were used. Age, nutrient condition, familial tendency and hormonal factors influence to breast physiologically. Normal breasts were classified into the standard (9.7%), ductal (71.7%), glandular (6.2%) and atrophic (12.4%) types. Ductal type was further subclassified into intraductal, periductal and mixed types. Atrophic type was subdivided into fibrous and fatty. Standard type was observed in younger women, instead of atrophic type was seen in older age group, especially after menopause. Periductal type was most common (65.4%). Glandular type was mostly in twenty to thirty year group. According to increase of age, glandular or ductal type transformed into atrophic type.