Bee propolis is a gelatinous solid substance with an aromatic odor and viscosity formed by the resin collected by bees from the young shoots of plants and mixed with secretions from the bees' palatine glands, a small amount of pollen, and beeswax (Colored Figure 23, Colored Figure 24).

Small information: China's common gum source plants include most tree species in the willow, pine, birch, cypress and lacquer families, as well as peach, plum, apricot, chestnut, rubber, eucalyptus and sunflower. Bees also collect the gum particles on the thorns, grayish color, light aroma, unknown composition, poor quality, also known locally as the ground gum. By artificial collection from the poplar tree buds, poplar leaves, through the press and alcohol extraction of the substances formed, called artificial poplar gum.

China's poplar-type, pine-type and birch-type propolis in the total flavonoid content is higher than the Brazilian propolis more than 5%, contains the anti-cancer substance caffeic acid phenethyl ester, the Brazilian propolis does not contain, the volatile oil contained in the Brazilian propolis than the low 2% strong.