Polyphenolic compounds are present in various edible plant sources and confer antioxidative properties making them nutritionally valuable agents against cancer and arteriosclerosis. This study was aimed at investigating the various effects of extraction temperature, extraction time and other variables intrinsic to the extraction process, on the yield of phenolic compounds from Soy hull. The phenolic content of Soy hull extracts were also quantitatively compared to that of notable sources such as green tea and grape skin. Total phenolic content was determined by the Folin-Ciocalteu method which involved UV-vis spectrophotometry and a calibration standard curve based on catechin standards. For comparative analysis of the soy hull, grape skin and green tea extracts, the extractions were all conducted using a 1:5 ratio of solute to 70% ethanol solvent and mixed for 1 hr at room temperature. The total phenolic contents of the green tea, grape skin and Soy hull extracts expressed as catechin equivalents (mg of catechin/ g of sample) were, 153.39 mg/g, 4.527 mg/g and 0.623 mg/g respectively. For Soy hull, increasing extraction temperature to 70C improved extraction efficiency, with a yield of 0.684 mg/g. At 80C, there was no marked increase in extraction efficiency which was lower than what was expected. This may be due to the presence of a rigid pectin framework. A preliminary study in our laboratory indicated that an acid digestion prior to extraction may improve phenolic compound extraction yield. The combined effect of temperature, acid treatment and extraction time on phenolic compound extraction will be reported.