Abstract: Frying process causes changes in physical, chemical, nutritional and sensory properties of oils. Some products that produced during this process have been implicated in producing adverse health effects as they destroy vitamins, inhibit enzymes and could cause highly oxidized oils may also produce polyaromatic hydrocarbons which have carcinogenic effects. The aim of this research is to determine the effect of deep frying using high temperature (200°C) on nutritional chemical characteristics of commercial oils that include iodine number, peroxide value, acid value and saponification number. Chemical analyses of potato were (80.61%) for moisture (0.22%) for fat (1.54%) for protein (98%) for ash and (46%) for fiber. Iodin number was decreased depend of increased of number of potato frying times. Significant differences (p#0.05) were observed for iodine number between types of oils as well as among number of frying times. Peroxide value, acid value and saponification number were increased depend on increased of number of potato frying times. Significant differences (p≤0.05) for these values between types of oils as well as among number of frying times. However, no significant differences were observed for saponification number between types of oils. Results from this research indicate that deep frying using high temperature (200°C) significantly affects the nutritional chemical characteristics of oils.