Objective To investigate the knowledge and willingness of genetic counseling and testing in blood relatives of breast cancer patients.Methods A total of 922 blood relatives of breast cancer patients finished our questionnaire.Data were devided into different groups according to age,family history of tumor for statistical analysis.Results Most of the respondents were unaware of genetic counseling and genetic testing.However,after a brief introduction,major of them were willing to accept genetic counseling,breast cancer risk evaluation and screening.Specifically,79.8％ of them were willing to accept genetic counseling,and 62.3％ were willing to accept genetic testing.Most of the respondents would accept inexpensive early genetic screening.For the genetic testing with higher prices,only 37.9％ of them would accept it.Supposing a positive genetic testing result,most of them were willing to perform prevention through close follow-upscreening,31.3％ of them would choose prophylactic surgery or drugs.Despite being told the confidentiality of the test results,32.9％ of them worried about the adverse effects of genetic test.Conclusions Most of the blood relatives of breast cancer patients were unaware of counseling and genetic testing,but had apparent willingness to accept them.Misunderstanding of genetic characteristics,costs and concerning about discrimination are obstacles for the respondents to accept genetic counseling,genetic testing and related screening prevention.