In the present work, the nature of an anticoagulant from Philipendula ulmaria was studied. A method for purification of this anticoagulant was developed. Using diverse methods it was shown that the molecular weight, data on element (sulphur, nitrogen, and hydrogen) content, spectral characteristics in the infrared region of the spectrum, and electrophoretic properties of the product indicate its similarity to heparin of animal origin.