In the present study the influence of thermal prcessing (namely, boiling, pressure cooking and microwave heating) on the in-vitro digestiblility of six dietary starch varieties were measured using the standard Englyst assay. The digestiblility of starches after thermal prcessin markedly affected by cooking methods. Cooking of starches by pressure cooking and microwave heating decreased the amylose content, increased the degree of gelatinization, and the amounts of SDS and RS were lost with a huge increased of RDS. The starch digestion index reached a maximum value about 80%. A inverse correlation was seen between hydrolytic starch fractions and amylose content from the data,while a positive correlation between hydrolytic starch fractions and degree of gelatinization. The results emphasize that cooking methods influence the nutritionally important starch fractions in different starchy food.