Lasiodiplodia theobromae causes decay of star apple fruits (Chrysophyllum cainino) during harvest, transport and storage. If the irradiation dose is higher than 800 Gy, this mold will be controlled. However, the quality of star apple was significantly changed when they were irradiated at the dose higher than 0.6 kGy by electron beam (EB). To keep irradiation dose under 0.6kGy, the synergic effect of the combined treatment of EB irradiation and sodium dichloroisocyanurate (NaDCC) was investigated. In this study, star apples were pretreated with NaDCC concentrations in range of 10 -70 ppm in order to decrease the growth of mold and extend the shelf-life of treated star apples. The results showed that pretreatment with 20 ppm NaDCC had also kept the color and reduced disease of stored star apple. Dipping star apples into 20 ppm NaDCC solution before irradiating at 400 Gy and 600 Gy could be chosen as the best way to inhibit the development of Lasiodiplodia theobromae and extend the shelf life of star apple in the trading condition (7 days, 9oC).