In order to study the risk factors associated with female breast cancer, two 1:2 matched case-control studies were conducted from 1986 to 1993 in five cities in Hubei province and from 1991 to 1994 in Pingdingshan coal mining districts in Henan province. The results of multivariate conditional logistic regression analysis showed that history of breast diseases, number of births, age of first birth were major risk factors for breast cancer in urban inhabitants. Their adjusted attributable risks (PARs) were 0.3917, 0.3564, 0.1414 respectively. The combined population attributable risks (PAR) for the three factors was 0.7419. History of breast disease, number of births, menstrual disorder, family history of breast cancer were major risk factors in the Mining districts. Their PARs were 0.1487, 0.4781, 0.1282, 0.0791 respectively. PAR for four factors was 0.6952.