The present invention provides a method of extracting an asymmetric β-diketone compound from a β-diketone compound containing at least one symmetric β-diketone compound mixed in the asymmetric β-diketone compound, and the method includes the step (A) of adjusting a pH of a mixed solution of the β-diketone compound and water at 11.5 or more and dissolving the β-diketone compound into water to form a β-diketone compound solution and the step (B) of subsequently adjusting the pH of the β-diketone compound solution at 9.5 or less and recovering the asymmetric β-diketone compound of Chemical Formula 1 separated from the β-diketone compound solution. The present invention further includes at least either (a) a step of setting the upper limit of the pH of the mixed solution to 12.5 to form a β-diketone compound solution in the step (A) and bringing the β-diketone compound solution into contact with a hydrophobic solvent or (b) a step of setting the lower limit of the pH of the β-diketone compound solution to 8.0 in the step (B).