Abstract: Levopimaric acid was isolated from turpentine by amination method and ultrasonic assisted recrystallization, and its physical and chemical data were experimental measured. By single factor and orthogonal test, the optimum isolation conditions of levopimaric acid were as follows:ethanol concentration 100%, crystallization temperature 0 ℃, volume ratio of ethanol used for crystallization 20 : 1(mL : g), ultrasonic frequency was 53 kHz, 2 recrystallization times; purity of levopimaric acid was 97%. Ultrasonic assisted crystallization was used to shorten the nucleation time of the levopimaric acid crystal, and a fine-uniform rectangular transparent crystal was obtained after 5-6 h. The molecular structure of levopimaric acid was characterized by FT-IR, NMR(¹H NMR, ¹³C NMR) and GC-MS. According to the oxygen elastic calorimeter, TG-DSC and group contribution, the standard molar enthalpy(Δ_fH_m^ɵ) and melting enthalpy of levopimaric acid were -700.23 and 94.99 kJ/mol, respectively.