The aim of this research is to control the pathogenic fungus, which causes Fusarium wilt disease in watermelon, Citrullus lanatus var lanatuscv. (Crimson Sweet 0015) by grafting it onto pumpkin, Cucurbita moschatacv. (Tetsukabuto). Pathogenic fungus was isolated from the infected roots of watermelon seedlings through growing it into PDA culture. In this study, Tongue approach grafting method was applied. Plants have been divided into four groups. Only two groups have been injected with spores of Fusarium oxysporum 1x106 conidia / ml, then plants were planted in industrial sterile soil contains peat moss and vermiculite (1:1 vol/vol) in pots at a completely randomized design. Finally, results of observations were collected after the disease symptoms appeared on the plants. The results and statistical analysis for data showed that grafting had a positive effect, where the grafted plants were better than non-grafted in all the measurements in terms of the weight of the shoot and root, the length of stems and roots, as well as the number and weight of fruits. These results also indicated that grafting of watermelon onto specific rootstock (pumpkin) has left a positive impact on plants disease resistance. Therefore, the results of this study conclude that the grafting is an advantageous alternative method to the control of Fusarium wilt disease in watermelon.