Cinnamon containsmuch number ofmedicinal properties. Cinnamaldehyde is one of the main compounds in the cinnamon. Cinnamaldehyde was highly effective in inhibiting the growth of microorganisms and acts as a presrvator. In this present study the fermentation process continues up to 17 days. The yeast growth was inhibited up to 12 days and shows to be increased from 12 to 17 days. The result shows best agreement for the Cinnamaldehyde to acts as a preservative up to 12 days for the inhibition of bakerÂs yeast used in food stuffs. The effect of fermentation process on Concentration of Cinnamaldehyde and Biomass from aqueous extract was determined and the specific growth rate (µ) 0.180 hr -1, the maximum specific growth rate (µmax)0.7627 hr -1 and the yield factor (Yx/s) 4.504 g/L were estimated.