The aim of this research, is to use Liquid–liquid extraction to separate phenolic compounds from olive mill wastewater resulted from three-phase centerfuge extraction (OMWW). Four solvents were used: Methyl iso butyl ketone (MIBK), Ethyl acetate (EtOAc), Octanol-1 (C8H18O), and Noctanoylpyrrolidine (OPOD) which was synthesized in our lab. The effects of pH and Extraction stages on the efficiency of total phenolic compound extracted from OMWW were determined by Folin - Ciocalteu spectrophotometric method. Ferulic acid (FA) and Caffeic acid (CA) were determined in extractants by HPLC. The COD value in water phase of the four extracts was measured together with the reducing power and radicalscavenging effects for the extracts. We compared the antioxidant activity of MIBK, OPOD extracts, with ferulic acid (FA), caffeic acid (CA), ascorbic acid standards and rosemary. The results showed that MIBK had the highest extraction efficiency and gave the maximum quantity of phenols from OMWW, than OPOD, C8H18O, EtOAc. The COD value was decreased about %94.5 by MIBK, %83.7 by OPOD,%81 by C8H18O, and%72 by EtOAc. The phenols extracted by MIBK could be added to eatable oils as natural antioxidants, because they were superiority on rosemary, and nearly to caffeic acid (CA) standard.