Experiment was conducted to measure the feasibility of using starch into soya flour for the preparation of acceptable quality of soyadahi. In the first phase of experiment, five samples of soyadahi were prepared from soy flour with the addition of different levels of starch. The dahi samples were designed as ‘A’ (control or without starch), ‘B’ (soydahi containing 0.5% starch), ‘C’ (soydahi containing 1.0% starch), ‘D’ (soydahi containing 1.5% starch) and ‘E’ (soydahi containing 2.0% starch). Quality of dahi was monitored by using physical, chemical and microbiological tests. From the results of physical study (smell and taste, Body and consistency, colour and texture) it was found that the overall score for A, B, C, D and E types of soydahi samples were 70.90 C , 80.40 AB , 83.50 A , 79.20 B and 74.10 C . The differences among them were statistically significant. Chemical tests for (%)moisture, (%)total solids, (%)ash, (%)acidity, (%)fat, (%)protein (%)carbohydrate and PH were done. From microbiological tests the average results of total viable counts were 1155, 2105, 3968, 4559, and 4235 respectively. Total viable counts increases due to addition of starch increasingly from 0% to 1.5%. Finally it is concluded that soydahi containing 0% starch is nutritionally good and soydahi containing 1.0% starch is best in the basis of organoleptic quality.