The local anesthetic activities of the anti-histaminic drugs have been studied. on the skin of frogs (hind legs) and cornea of rabbits. 1) The anti-histaminic drugs, such as Restamin (Benadryl), Pyribezamine, Anergen (3115 RP) and Anahist, have an apparent local anesthetic action on the skin of frogs and cornea of rabbits. The order of anesthetic potency of these compounds is as follows : Anergen>Restamin>Pyribenzamine>Anahist. The local anesthetic potency is more apparent at pH 7.2 of solution than at pH 6.6. 2) Anti-histaminic drugs intensifies the local anesthetic action of another anti-histaminic or of local anesthetics on the skin of frogs. 3) When anti-histaminics in, high concentration are applied with local anesthetics to the cornea of rabbits, the duration of anesthesia decreases, but anti-histaminics in low concentration augment the anesthetic activities of local anesthetics. 4) The permeability rate of procaine through the cornea of rabbits is increased by Restamin and Pyribenzamine either in vivo or in vitro. 5) The permeability rate of anti-histaminic drugs (Restamin, Pyribenzamine) and local anesthetics (Procaine, Narcaine) are influenced by pH of the applied solution.This rate is higher at pH 7.2 than at pH 6.6.