Abstract: We conducted this study to determine the effects of low energy diets (i.e., food restriction) on the oxidative stress indices of ewes in late pregnancy. About 21 clinically intact Ghezel ewes with an average weight of 50±3 kg used for the study. They subjected for oesterus synchronization by using CIDR. Data were analyzed using split-plot design in time. The major factor of T in two levels (T₁: food restriction; T₂: control) and the 2nd factor P in four levels (P₀: control or 4th week of pregnancy; P₁: overnight feed deprivation treatment in 5th week; P₂: 1st food restriction treatment in 14th week; P₃: 2nd food restriction treatment in 19th week (8th week to probable date of gestation)). Serum concentration of glucose, BHB: β-hydroxybutyrate; NEFA: Non Esterified Fatty Acids; MDA: Malondialdehyde and activities of SOD: Superoxide Dismutase and GSH-Px: Glutathione Peroxidase in red blood cells and TAS value measured in those periods. The findings showed that there is a statistically significant difference between BHB and NEFA (p<0.05) and TAS: Total Antioxidant Status of different treatments (p<0.01). In addition, NEFA, BHB, TAS, MDA, SOD and GSH-Px had statistically significant difference in periods (p<0.05). Only BHB and TAS were statistically significant difference in T*P, respectively (p<0.01 and p<0.05). We concluded that in comparison with food restriction, pregnancy period was the major agent for oxidative stress in late pregnancy of Ghezel ewes. We also concluded that food restriction had not a significant effect on oxidative stress indices. However, period of gestation especially in late pregnancy imposed lots of stress on anti-oxidative system of ewes.