A crystalline form VI of agomelatine having X-ray powder diffraction diagram and infra-red spectrum as given in the specification, is new. A crystalline form VI of agomelatine of formula (L1) having X-ray powder diffraction diagram and infra-red spectrum as given in the specification, is new. An independent claim is included for preparation of the crystalline form VI of agomelatine (L1). [Image] ACTIVITY : CNS-Gen.； Hypnotic； Tranquilizer； Antidepressant； Cardiovascular-Gen.； Immunomodulator； Muscular-Gen.； Neuroleptic； Anorectic； Analgesic； Anticonvulsant； Antidiabetic； Antimigraine； Cytostatic； Antiparkinsonian； Endocrine-Gen.； Nootropic. No biological data given. MECHANISM OF ACTION : Melatoninergic system receptor agonist； 5-Hydroxytryptamine 2c receptor antagonist. No biological data given.
