To provide a water-based electroconductive coating material capable of improving the electroconductivity, and its manufacturing method.

The water-based electroconductive coating material, a water-based electroconductive adhesive, is manufactured by using water (pure water) as a solvent, adding an expanded graphite as an electroconductive particle into it in 1-10 mass% together with a water-soluble binder, e.g. PVA, in 2.6 mass%, and further adding a graphite as an electroconductive particle in a required amount (so that the total amount of it and the expanded graphite becomes 10 mass%), and agitating it for 24 hours, e.g. by a Turbula mixer. There is used as the expanded graphite one that has an expansion volume of 100 cc/g or larger, e.g. of 200 cc/g.