The therapy for breast cancer (BC), to date, still needs improvement. Apart from traditional therapy methods, biological therapy being explored opens up a novel avenue for BC patients. Integrin β1 (ITGβ1), one of the largest subgroups in integrin family, is a key player in cancer evolution and therapy. Recent researches progress in the relationship of ITGβ1 level and BC, finding that ITGβ1 expression evidently concerns BC progression. In this chapter, we outline diverse ITGβ1-based mechanisms regarding to the promoted effect of ITGβ1 on BC cell structure rearrangement and malignant phenotype behaviors, the unfavorable patient prognosis conferred by ITGβ1, BC therapy tolerance induced by ITGβ1, and lastly novel inhibitors targeting ITGβ1 for BC therapy. As an effective biomarker, ITGβ1 undoubtedly emerges one of targeted-therapy opportunities of BC patients in future. It is a necessity focusing on scientific and large-scale clinical trials on the validation of targeted-ITGβ1 drugs for BC patients.