Floating drug delivery system is the gastro retentive systems can remain in the stomach for many hours and can significantly prolong the gastric residence time of drugs. The aim of the work is to design floating tablets of Ondansetron for gastric retention by using 32 factorial designs. Chitosan and Sodium Bicarbonate is used as independent variables were as time taken to release 50% and floating lag time is dependent variables. Floating tablets of Ondansetron were prepared by direct compression method using polymers and sodium bicarbonate. Floating tablets were evaluated for floating time, floating lag time, drug content and in vitro dissolution profile. The lag time is between 25-10 sec and floating time of the formulations stopped on 12 hrs, Drug release percentage is upto 90-94 % and kinetic studies were carried out and best batch is F9, The best fit model is Korsemeyer Peppas Model. From the study it is proof that the sustain release by floating tablets of Ondansetron can be develop.