This study was conducted having the goal of investigating the effects of Methyl Jasmonate on germination, growth and development indices and fruit yield in melon cultivars through two experiments separately performed at Labarotary and Research Station of Agricultural College, Shahid Bahonar University of Kerman in 2011. Germination test was conducted as a factorial experiment on the basis of completely randomized design with seed soaking in Methyl jasmonate at 5 levels (0, 1.25, 2.5, 5 and 10 μM), two levels of the cultivar (Shapasandi and Annanasi), four replications and each replication consisting 500 seeds. The field experiment was performed as split split plot using randomized complete blocks with seed soaking in methyl jasmonate at three levels (0, 5 and 10 μM), spraying jasmonate at two levels (0 and 5 μM) and ethephon spraying at two levels (0 and 300 ppm) with four replications. The results of germination experiment demonstrated that the highest germination percentage (81.6%) and germination rate (6.74 seeds/day) was related to the 5 μM concentration of methyl jasmonate. Shapasandi cultivar had superiority over Annanasi cultivar. In the field experiment, the Jasmonat pre-treatment increased leaf area in Shapasandi cultivar by 39.2%. It was showed that the chlorophyll index (7.7%), leaf number (19.2%), as well as the number of fruits (40%) were increased in the presence of 5 μM of jasmonate. The 5μM seed pretreatment was superior to Jasmonat spraying in terms of increasing the fruit yield. Jasmonat spraying increased fruit weight and flesh thickness in Shapasandi cultivar. Seed pretreatment with 5μM jasmonate can be recommended for increasing the yield of Shapasandi and Annanasi cultivars.