The quality of soybean oil (SO) and refined palm oil (RPO), frying at 180ºC for 12 h was investigated. The purpose of the study was to find out the quality deterioration of the two oils with respect to time as affected by fritters frying and to generate equations that can be used for predicting the quality parameters. The physicochemical characteristics of two oils were evaluated by taking the oil samples (100 mL) in the pan (fryer) after 1h of frying. The parameters evaluated were K233, K269, viscosity, polar compounds, fatty acids methyl ester analysis by Gas Chromatography (GC), Differential Scanning Calorimetry (DSC). There was a gradual increase in K233, K269, viscosity and polar compounds with during frying of the two samples. Linoleic acid was degraded during frying in the two oils. Viscosity correlated well (r > 0.99) with polar compounds and time of frying. K233 and K269 correlated well (r > 0.99) with during frying, polar compounds duration of frying and absorption capacity of oils in fritters.