ABSTRACT Muskmelon is a highly valued fruit in Japan. In addition to local greenhouse production of melon in Japan, there is substantial import to meet local demand. Oman has emerged as an exporter of vegetables to Japan with the introduction of snap beans as a lead crop. Muskmelon appears to be another candidate crop for export from Oman. Owing to strict quality standards followed in Japan, it was found necessary to investigate quality, especially sweetness, of Omani melon to meet Japanese market requirements. Three experiments were undertaken viz, evaluation of 32 Japanese cultivars grown in Oman under Omani methods; evaluation of Omani cultivars grown by Japanese methods in Spring; and evaluation of Omani cultivars grown by Japanese methods in Fall. From the experiment of evaluation of 32 Japanese cultivars in Spring 2005, the top eight cultivars Andersen, Smash melon, Aristo seika, Rockstar, Lewis, Picaso Melon, Bonus 2gou and Monami red showed the highest quality which having TSS 10% and more, thus they can be considered for future testing. Comparing 32 Japanese cultivars with a local control, average TSS percentage did not show significant differences (P<0.05). Average fruit weight and length of 32 cultivars were lighter and shorter than the control. This is probably because the number of fruits per plant in 32 cultivars was higher than that of the control. The results indicate that Japanese high quality melon is not primarily due to cultivar characteristics but rather to other factors. In the experiments of Spring and Fall 2006, one cultivar, Sunrise, was used and cultivated by applying some Japanese cultivation methods, that is, topping bud, trimming branches, guiding leaves and branches, planning fruit setting position, and thinning fruit. TSS 13% was not obtained by all treatments. Since fruit setting position must have risen higher than the planned position due to damage by fruit fly in spring 2006, different results were obtained from experiments in Spring and Fall 2006. Compared with the control which was cultivated by Omani cultivation methods, melon grown by some of the Japanese methods had less TSS percentage, width, and circle ratio, and higher weight and length than those of the control in Spring 2006, however, none of them showed significant differences in Fall 2006. TSS percentage had significant interaction with fruit weight, length, width and number of fruits per plant in Spring and Fall 2006. However, fruit set position interaction with TSS percentage, and fruit weight, length and width showed different results in Spring and Fall. This study is at early stage. Further studies includin other Japanese practices, that is, making a ridge in the field and precise irrigation and fertilization are needed in combination with the effect of fruit set position.