We report a new experimental allergic conjunctivitis with Japanese cedar pollen as antigen in guinea pigs, and the immunological characteristics of this model were also elucidated. Allergic conjunctivitis was developed by immunization in guinea pigs with a mixture containing Japanese cedar pollen and killed Bordetella pertussis. When local application of Japanese cedar pollen suspension 14 d after systemic immunization was performed every 3d, remarkable conjunctivitis was observed from 20 to 35 d. Increase in vascular permeability and decrease in histamine contents of the conjunctiva were also observed after local application of antigen. Passive cutaneous anaphylactic (PCA) reactions revealed that both IgG- and IgE-rich antibodies were produced in this model. Chlorpheniramine, ketotifen and levocabastine were effective in inhibiting cedar pollen-induced conjunctivitis. Although a high concentration was needed, tranilast and amlexanox also showed significant inhibition of conjunctivitis induced by cedar pollen.