Objective:To investigate the relationship between common breast disease and ABO blood group in Hans of Guangdong Province. Methods:We analyzed the ABO blood group distribution of 1267 patients of mammary gland disease and 1005 healthy controls in Hans of Guangdong Province. Results: The distribution of ABO blood group in patients of breast cancer,hyperplasia of mammary gland and breast fibroadenoma had no significant difference with control groups(P>0.05). The relative risks of breast desease were similar a...