Immunoglobulin E (IgE) is a key mediator for the immune reaction in airway mucosa and plays a vital role in nasal polyposis(NP). We review the most recent evidence for the local IgE’s characteristics, the modulation of its synthesis and function in NPs. The level of local IgE is significantly elevated in polyps independently of IgE serum levels and atopic status. Furthermore, local IgE is polyclonal and functional, which is correlated with type 2 inflammation. IgE is produced by active B cell and dependent on the classing switch recombination(CSR). In NPs, this process is triggered by not only allergens but also microbial colonization, especially the superantigen- Staphylococcus aureus. The production of local IgE is modulated by lymphocytes, cytokines, transcription factors and B cell intrinsic factor. Due to the central role of IgE in NPs, it is regarded as an ideal target for therapy and has been proved to be clinically successful. Based on this knowledge, we believe that exploring the trigger and regulatory factors for the activation of local B cells and CSR to IgE will provide more valuable information for us to recognize the pathological mechanisms of local IgE and offer the possible option for new therapeutic targets of NPs.