Endogenous gibbereliin and auxin activities and tolerance to fusarium wilt disease in spinach in summer cropping were higher under near-ultraviolet eliminating polyvinyl chloride film (UVE) than under near-ultraviolet transmitting polyvinyl chloride film (UVT). Gibbereliic acid (GA_3) treatment after inoculation of Fusarium oxysporum f. sp. spinaciae gave the various results on disease severity depending on the concentration and the films. Endogenous hormone activities were lower in the inoculated plants treated with GA_3 than those in uninoculated plants without GA_3. These hormones do not seem to act directly to the pathogen, but seem to increase the tolerance of the plants by increasing the growth and vigor.