Basic leucine zipper protein refers to a grand transcriptional factor family of all eukaryotes that is involved in various developmental and stress responses like flower development, plant height, maturation of seeds, biotic and abiotic stress signaling. About 127 bZIPs in Arabidopsis, 70 in cotton (Gossypium hirsutum), 266 in soybean (Glycine max), 47 in tobacco (Nicotiana tabacum), 70 in tomato (Solanum lycopersicum), 140 in rice, 102 in wheat and 218 in maize have been discovered. In this review, the classification of bZIP is according to the binding specificities of bZIPs as well as their role in transcription.