To provide easily drinkable Isatis tinctoria L. tea excellent in the decoction of active ingredients.

This method for producing a medicinally active tea comprises spraying and adhering the concentrated extract solution of a medicinally active ingredient-containing plant to the surfaces of tea materials comprising tea leaves or their substitutes and subsequently drying the tea materials. Therein, the process for producing the concentrated solution comprises a decoction concentration process for decocting the medicinally active ingredient-containing plant, filtering the obtained extract solution and subsequently concentrating the filtrate, and a decomposition concentration process for adding alcohol to the concentrated solution to decompose fat-soluble ingredients and subsequently again concentrating the solution. The tea leaf material includes the withered leaves of Isatis tinctoria L.