Abstract: AIM To study the stability of ligustilide with solvent effect and try to disclose the relationship between its stability and solvent effect, so as to develop a useful method for its preservation. METHODS The model of PCM solvent effect was used to carry out quantum chemistry calculation. The GC/MS spectrum was used to study the stability of ligustilide in solvent at room temperature. RESULTS Ligustilide is more stable in cyclohexane and chloroform than in air. The isomerization rate of ligustilide decreased remarkably to 1.6% and 6.7% in cyclohexane and chloroform compared to 58% in air. CONCLUSION The stability of ligustilide is greatly improved with the solvent effect. Keeping ligustilide in proper organic solvent is helpful to prevent its isomerization.