To inspect the effect of methyl salicylate (MeSA) vapor on fruit shelf life quality in kiwifruit (Actinidia chinensis cv. Hayward) an experiment was carried out in Citrus Research Institute, Ramsar, Iran in 2006-2007. The experiment was based on a completely random design of three replications. The treatments consisted of MeSA at five rates (0, 8, 16, 24 and 32 µL/L) and storage time of five levels (every month of five month duration of shelf life during the whole period of the experiment. Assessed qualities included: Total Soluble Solids (TSS), Titrable Acidity (TA), vitamin C, pH, firmness of pulp, activity of Ascorbate peroxidase (APX) and fruit ethylene production. The results of the experiments revealed that treatment with 32 µL/L of MeSA had the greatest effect on delay of postharvest ripening of fruits. Fruits treated with 32 µL/L of MeSA had a slower trend in decrease of pulp firmness and vitamin C as well as a slower trend in increase of TSS, ethylene production, and APX activity during storage as compared to control. Fruit TA decreased during shelf life period but MeSA did not have a significant effect on this trait. The highest delay effect of MeSA application on decrease trend of pH was observed in the 24 µL/L of MeSA application treatment.