Cyanobacteria possess physiological characteristics that allows them to inhabit a variety of places with a high degree of success. Maintenance of efficient cellular functionality under ever changing environmental conditions is aided by the ability of cells to by selectively redistributing metabolites among different pathways. My study focuses on metabolic characterization of some fast growing local isolates of cyanobacteria using 13 C metabolic flux analysis tool and compare them with few model cyanobacterial strains. The detailed understanding of the metabolism would help us to engineer these local isolates of cyanobacteria as a suitable host for industrial applications.