One – group pretest – posttest research design was conducted with 60 women aged 34 to 80 in Dong Quang ward, Thai Nguyen city. The results of this study show that, the mean score of knowledge about breast cancer before and after intervention by health education that was statistically significant difference (Mean score = 8.83; SD = 5.43; Mean score = 30.28; SD = 5.79; p <0.000). The percentage of women practicing regular BSE was determined as 36.1% before training, 80.0% after 3 months (p <0.000). Conclusion: The findings of this study show that, need to further expand health education to promote breast cancer knowledge as well as practice breast self-examination, and breast cancer screening in a way that is appropriate for each individual ages. These interventions will further strengthen breast cancer prevention, screening and detection at an early stage, thereby reducing breast cancer mortality