Bacterial antibiotic resistance has become a serious problem facing the world today. The rapid spread of mobile genetic elements (MGEs) carrying antibiotic resistant genes between the same or different bacterial species has accelerated the formation of antibiotic resistance, posing a huge challenge to clinical treatment of bacterial infections. The insertion sequence (IS) is the simplest MGE, which encodes a transposase gene and has reverse terminal repeat sequences on both sides. The IS91 family is one of the 26 known insertion sequence family, with 34 members to its name. Recent studies have shown that many members of the IS91 family are strongly associated with antibiotic resistance. Therefore, this article will review the discovery and genetic characteristics of IS91 family, similarities and differences between IS91 and insertion sequence common region(ISCR), as well as their relationship with drug resistance and virulence gene transmission, so as to provide reference for future research on bacterial drug resistance.