This study was carried out to investigate the variation of mulberry yield in various parts of mulberry field. The results obtained from the study are summarized as follows. 1. For all the varieties, higher yield was observed side part than in the middle part. 2. With respect to the direction of field, the side faced south produced the highest yield, which was followed both side parts faced east and west. The side part fated north also produced relatively high yield. 3. No significant difference in yield was obtained between the central part and the near the each side, even the former seemed to be some what higher in yield than the latter. 4. Such a variety as Kaeryangsuban havins small leaves on many twigs with small internodes appeared to have more side effect than the otherwise variety, i.e. Rosang. 5. The variety Kaeryangsuban, showed more side effect in spring than in Autumm, however Rosang showed reversed effect. 6. Similar results were obtained in the leaf dry weight. 7. As a conclusion, it can he an important factor to increase yield to set up the mulberry field in east and west resulting less side effect.