To optimize the fermentation period of lightly salted Oiji, 3% salt was added to cucumbers that were fermented at 27±1°C for 3, 4, 5, 6, or 7 days, after which their physical properties (moisture content, salinity, pH, acidity, hardness) and sensory characteristics (acceptance test, difference test) were evaluated. The moisture content was highest at day 6. Hardness slowly increased as fermentation time increased, but not significantly. The pH was highest after 3 days of fermentation, and tended to decrease as fermentation time increased, with the largest drop occurring between 4 and 5 days, and the lowest pH occurring between 6 and 7 days. Acidity was lowest after day 3 of fermentation and highest after day 7. Acidity tended to increase as fermentation period lengthened. The L-value tended to decrease as salt concentration increased. The a-value declined from day 3 to day 5, then increased significantly by day 7. The b-value was highest after 7 days, with a tendency to increase as the fermentation progressed. Acceptance test results were highest for taste and overall acceptance after 5 days of fermentation. The difference test showed that the optimal lightly salted Oiji fermentation period was approximately 5 days. These results indicate that lightly salted Oiji fermented for 5 days produced the highest acceptance.