PURPOSE: To obtain a readily ingestible tonic beverage, containing drug effective ingredients beneficial to bodies and ingredients optimum for nutrition by using an extract of Houttuynia cordata Thunb. and acetic acid as principal ingredients.

CONSTITUTION: Stems, leaves or roots of Houttuynia cordata Thunb. are washed with water, removed from sticking soil bacteria or molds, drained and then finely cut. The resultant stem, leaves or roots are subsequently dipped in acetic acid, kept at about 40°C for 5 days and fermented. A sweetener is suitably added thereto and the obtained mixture is filtered to provide a solution, which is then thermally sterilized at 80°C for 30min to afford a tonic beverage consisting essentially of an extract of the Houttuynia cordata Thunb. and acetic acid. A half-boiled egg, as desired, is dipped in the aforementioned tonic beverage, allowed to stand at about 35°C liquid temperature for 2 days and the whole is then stirred to afford a mucilage, which is subsequently filtered and sterilized to afford a tonic beverage consisting essentially of the Houttuynia cordata Thunb., acetic acid and half-boiled egg.