Many studies show that as a transcription factor, B lymphocyte-induced maturation protein 1 (Blimp 1) is the master regulator of plasma-cell differentiation. The abnormality of Blimp 1 plays an important part in the genesis and development of lymphoma. This review introduces and summarizes Blimp 1's protein structure and functions, its role in B cell differentiation, its main target genes and the mechanism of its transcriptional repressor activity. Besides, the relationship between Blimp 1 gene mutation or Blimp 1 protein expression reduction and the development of DLBCL is preliminary summaried.