An endeavour of present study is to optimize the method for determination of swelling factor of Ispaghula seeds, so it can be determined correctly with minimum errors which will be reproducible. The polysaccharides in the mucilage of Plantago seeds constitute a diverse class of biological macromolecules with a broad range of physiochemical properties which are widely used for applications in Pharmacy and medicine. Many official and unofficial sources described different methods for determination of swelling factor with variable results. The present work is undertaken to determine the effect of parameters such as quantity of seed, volume and nature of solvent, time interval of agitation, time of measurement of result, Effect of quantity of seeds on swelling factor determination. Swelling factor of different seeds like Lepodium sativum, Althia officinalis and Occimum sanctum has been evaluated by IP method and optimised method for 24 h. Optimized method gives superlative results over IP method. Plantago seeds moistened with 1ml of 90% alcohol followed by addition of distilled water at room temperature along with every 3 h agitation shows exceptional swelling as compared to other methods and conditions.