Substitute for cement is the global research need and apart from high volume flyash concrete. The recent research on the bulk utilisation of flyash is the development of GPC to promote the green concrete avoiding the CO2 emission from cement production and finds its way in a most typical means of development. This article brings out the development of low calcium flyash based GPC to achieve the required equivalent characteristic strength of 30MPa. GPC with different molarity of sodium hydroxide in the activating solution is produced by both hot and ambient curing methods for comparison. The activator/ flyash ratio by mass is taken as 0.35 and the liquid ratio as 2.5. It is concluded that, ambient curing is adequate for low calcium flyash based GPC.