To obtain an additive for water permeable concrete which can prevent separation of a cement paste from an aggregate, and to provide water permeable concrete which includes the additive.

This additive for water permeable concrete consists of a water- absorbing resin and a water-soluble resin, where the water-absorbing resin is at least one species selected from a crosslinked product of polyacrylic acid (salt), a crosslinked product of polyethylene oxide and water-absorbing polyurethane. The water-soluble resin is at least one species selected from guar gum, carboxymethylcellulose, hydroxyethyl-cellulose and polyvinyl alcohol. The mixing ratio of the water-absorbing resin to the water-soluble resin by weight (water- absorbing resin/water-soluble resin) ranges 20/80 to 95/5.