PURPOSE: A liquid laser medium and a manufacturing method thereof are provided to solve the problems of solid laser and prevent the movement of vibrational excitation energy by providing a new form of liquid laser medium which allows laser emission right after the medium is cooled. CONSTITUTION: A liquid laser medium includes 10 to 20 mmol of tterbium acetate monohydrate, 20 to 28 mmol of 1,1,1,5,5,5,-hexafluoro-2,4-pentanedione, and 1 to 3ml of methanol. These components form a synthesized Yb(SOL-H)3. Yb(SOL-D)3 is formed after Yb(SOL-H)3 is melted. A manufacturing method of the liquid laser medium includes the following steps. Dissolving 10 to 20 mmol of tterbium acetate monohydrate. Combining 20 to 28 mmol of 1,1,1,5,5,5,-hexafluoro-2,4-pentanedione and 1 to 3ml of methanol into the dissolved liquid above. Creating reactions and synchronizing for 24 hours. Collecting powder after vaporizing ion water and methanol. Collecting Yb(SOL-H)3 after refining acetone and methanol. Obtaining Yb(SOL-D)3 after creating reaction of Keto-Anol.