The crop of the early ripening Satsuma mandarin, 'Miyagawa Wase', is commercially har- vested in early November but it is sometimes left unharvested until February as the quality improves. The crop from the delayed harvest is referred to as Jujoh-Kanjuku-Ka which, in Japanese, is translated as fruit fully matured on the tree.'Miyagawa Wase' fruits from general orchards located on a flat land previously used as a rice paddy (C), stored from C (CS), which were harvested in November, and those grown in unheated plastic film greenhouse (H) were compared with those left on the tree until February (TB). In addition, the quality of 'Mukaiyama Unshu' fruits from a fairly flat hillside orchard (F), also general orchard, was compared with fruits from the famous orchards (I1-3) located on a steep hillsides in the Arita district of Wakayama Prefecture.Furthermore, seasonal changes in large and small 'Miyagawa Wase' fruits and fruits co-vered with different materials during the 13 months harvest period were also evaluated.1. The TB and H fruits had higher sugar contents than did those of CS and C. Fruits from I1-3 were sweeter than were those from F; those from I3 being the sweetest among the hill-side fruits. Sucrose was the predominant sugar, followed by fructose and glucose. As the total sugar content increased, the fructose level increased disproportionately. Sugar levels in TB and H were similar to that of I3.2. Titratable acidity was relatively higher in TB, H, and I1, whereas it was low in CS.3. Total amino acid level was high in fruits from I1-3; it was detected and appreciated by the taste panel. Among 'Miyagawa Wase' fruits, those from H had the highest amino acid content, whereas those from TB contained the lowest.4. Of the fruits harvested at different times from the general and famous orchards, those left on the tree until February had the highest sugar content. Although the sugar content increased from November to February, the differences in the sugar contents detected in November among fruits from the different sites were maintained until February.5. Compared with the large on the upper branches, small from the lower branches contained more sugar in November and they kept accumulating more sugar until they were havested in February.6. Enclosing fruits in paper bags on the branches prevented many kinds of possible inju-ries; the use of two bags decreased the sugar content and increased total acidity. Thus, we conclude from our findings that by delaying harvest in general orchards, it is pos-sible to produce sweeter fruits with higher acidity and possessing organoleptic quality as good as those from famous orchards located in superior production areas.