The present study was aimed at the development of stomach specific drug delivery systems using natural polymer. It concerns with the development and optimization of a formulation of in-situ gel of famotidine. The polymer used in the formulations is locust bean gum and sodium alginate. Nine different formulations were prepared by varying concentration of locust bean gum sols and calcium carbonate in demonized water where as the concentration of sodium alginate and tri-sodium citrate remain constant. The amount of drug is kept constant for all nine formulations. From the result we found that F6 formulation showed optimum drug release. The % drug release from the optimized formulation was found to be 98.9 % after 24 hr and viscosity 28.7 centipoises, thus batch F6 was selected as an optimized formulation because it shows more controlled release, which exhibited a drug content of 97.8 % and has a floating time of more than 24 hr. Stability study was done according to ICH guidelines. This study reports that the aqueous solutions of famotidine drug containing locust bean gum and sodium alginate forms in-situ gel in acidic environment as well layer formation occur on the mucous membrane of stomach