Boil water in a saucepan. Add jujube, ginger and cinnamon stick in it. Boil until water remains 1/4 part.
Strain jujube decoction through the sieve by smash.
Add sugar and small ginger piece to strained liquid. Pour it into a blending jar. Blend for a minute.
Transfer into a serving glass with some ice cubes and serve chilled.