Abstract: Plant acid invertase is one of critical enzymes in sucrose metabolism and plays an important role during plant growth and development. In the last decade, acid invertase genes have been cloned from many plant species, and great progress has been made in studies of the regulation of expression of these genes. This paper summarizes the research in elucidating the structure of acid invertase genes and proteins, regulation of gene expression by organ and developmental specificity, sugar, wounding, pathogen infection, stress and hormones, and regulation of enzyme activity by proteinous inhibitors. Problems in this field are also discussed.