Galanthamine and lycorine are known to possess important biological activities, widely distributed alkaloids in the members of Amarryllidaceae family. Also galanthamine is used for the treatment of mild to moderate Alzheimer's disease. In this study, the contents of these alkaloids have been quantitatively analyzed by high-performance liquid chromatography (HPLC) coupled with diode array detector (DAD) in the aerial parts and bulbs of Galanthus fosteri Baker collected from Akdag, Amasya during flowering and fruiting seasons. The chromatographic separation was performed using an isocratic system with a mobile phase of trifluoroacetic acid-water-acetonitrile (0.01:90:10, v/v/v) applied at a flow rate 1mL min(-1) using diode array detector. A simple extraction method utilizing columns pre-packed with diatomaceous earth (Extrelut (R)) was used. Validation procedures displayed that the method was specific, accurate and precise. Galanthamine was only detected in the aerial parts of the fruiting season with 0.0088 % average value. Also lycorine was only detected in the bulbs of flowering season with 0.0045 % average value.