The present invention relates to a formulation comprising Rebaudioside A (RebA) and Glycyrrhizin, wherein the water extracted 98% pure Rebaudioside A is mixed with 98% pure Glycyrrhizin extracted by hydro alcohol in the ratio of 70:30 in the composition along with filler and additive. The Present invention provides a composition for preparing natural sweetener having zero-bitterness taste and zero calorie profile and causes no. side effect on human health