Abstract: In the plant vegetative growth, leaf primordia arise from groups of initial cells within the peripheral zone of the shoot apical meristem.Leaf develops by following a series of cell division and differentiation programs to form its final shape and size. Recent genetic and molecular studies have led to the identification of a number of genes that regulate leaf development, and have also revealed that plant hormones play important roles in leaf primordium induction and leaf patterning.The challenge now is to further identify new players regulating leaf development and to establish the genetic interaction between regulatory genes as well as the relationship between gene regulations and hormone actions.