This research aimed to study some factors affecting the artificial curing of onion bulbs and its effects on the storability of bulbs in terms of (total soluble solids TSS and onion storage losses) comparing with the conventional curing method in Egypt. The study also aimed to determine the influence of different levels of  maturity stages (harvesting time), about of 20, 30, 40% and 50 % tops down and bulb sizes (large, medium and small) on the change in the bulbs moisture content and the time required for complete curing. The obtained results showed that, during field curing, the bulbs moisture content decreased gradually from initial moisture of 87-90 % ±0.5% (w.b) to a final level of 81.5 % ±0.5% (w.b) after 16 day (384 h). At maturity stages of 20, 30, 40, and 50 % of tops down, the results revealed that, curing of onion bulbs artificially can reduce the required time of curing by about 68.8, 71.9, 75 and 81.3 % for large size of bulbs, and by 71.9, 75, 78 and 81.3 for medium and small size of bulbs, compared with traditional curing method of bulbs (control treatment). The results also showed that artificial curing of bulbs at 20, 30, 40, and 50% of tops down, may save the time required for curing bulbs comparing to traditional curing method of onion bulbs, that in turn increase the available time for preparing the land of the next crop (maize, rice and cotton crops; and other summer vegetable crops) by about 13, 13.5, 14 and 15 day when curing large size of bulbs, while it save about 13.5,  14, 14.5 and 15 day when curing medium and small size of bulbs. The storability of onion bulbs improved with about of 12.73 % for bulbs harvested at 40 and 50 % tops down, while it was 12.44 % for bulbs harvested at 30 % tops down comparing with traditional curing.