This study evaluated the effectiveness of acidic electrolyzed oxidizing water (AEW), to control Fusarium sp. which causes postharvest disease of de-crowned pineapple cv. Phu Lae. The growth inhibition of Fusarium sp. in vitro was observed with AEW with avarious concentration with free chlorine at 100, 200 and 300 ppm. AEW treatment of 300 ppm was the most effective to suppress the growth of Fusarium Additionally, the AEW treatments enhanced the pathogenesis realated protein (PRs) β-1, 3-glucanase (EC 3.2.1.6) and chitinase (EC 3.2.1.14) activities after inoculation, which play important roles in plant defense responses. The increased activities of the enzyme were probable because the defense response to wide aray to stress including wounding and inoculating with Fusarium and treatment of AEW. Application of AEW enhances resistance of the pineapple fruit to fungal pathogens and has no effect on fruit's quality. 