In situ gel-forming systems have been widely investigated as vehicles for sustained drug delivery. In situ gel formation occurs due to one or a combination of different stimuli like pH change, temperature modulation, and solvent exchange. So, In situ gelling system via different routes such as oral, nasal, ophthalmic, etc can be formulated. In the present research work Oral Floating Insitu gel of Captopril was formulated using Sodium alginate. The optimized batch gave drug release for 7 hrs in the polymer combination of Sodium Alginate 1% and sodium bicarbonate 1.25%. It was found to be floating for more than 12 hrs. The batch was found to be stable for 2 months of instability study.