BZIP are a class of dimeric sequence specific DNA-binding proteins, is bipartite in structure containing region of enriched basic amino acids which is adjacent to leucine zippers. It is characterized by several leucine residues regularly spaced at seven amino acid intervals, basic region directly contacts with DNA. The leucine zipper mediates heterodimerization and homodimerization of protein monomers through parallel interactions which is unique to eukaryotes. The plant Arabidopsis thaliana genome shows 67 BZIP proteins. We have predicted dimeric properties of alpha helical leucine zipper and coiled coil structure of BZIP proteins in plants. In this analysis the length of leucine zippers, placement of asparagines in the hydrophobic interface and presence of interhelical electrostatic interactions were focused. Phylogenetic tree was also constructed by studying evolutionary relationship of BZIB existing among the plants.