Breast cancer is the most common cancer among women. The mammography exam is used as a form of screening and has as its main objective the early diagnosis of the disease. Thus, it is extremely necessary to use the "Programa de Controle e Garantia de Qualidade (PCGQ)" and the "Programa Nacional de Qualidade em Mamografia (PNQM)", which aim to ensure the reproducibility of the same image standard to facilitate the diagnosis of breast cancer. The tests performed by these programs are done with the aid of a human tissue simulator, also known as phantom. Thus, in this work a comparison of mass attenuation coefficients and density was made for polymers and copolymers used to simulate breast tissues composed of 50% adipose tissue and 50% glandular tissue. Eleven materials were analyzed: PLA, ABS, PC, PET-G, TPE, TPU, HiPS, Nylon or PA, Wood, PMMA and dental wax. This work aimed to verify which material is the best to simulate the breast tissues according to mass attenuation coefficients of each material. The results were compared with the values given by the International Commission on Radiation Units and Measurements - ICRU, report nº44, by the International Commission on Tadiation Protection - ICRP, report nº89 and by the composition of the infiltrating ductal carcinoma. For the mammography energy range this study indicated that the materials PLA, Wood and PC best simulate the ICRU 50%/50% breast; for ICRP were PETG, TPU and PMMA; for the skin were PC, PLA and Wood; for ductal carcinoma were PC and PLA.