Onion is one of the important commercial vegetable crops grown on a large scale in many countries.  As the onion bulbs are to be stored for long period for use during off-season, a considerable loss occurs by way of deteriorating, sprouting, and moisture evaporation during storage.This study was conducted to investigate the effect of storage conditions on the quality parameters of onion bulbs, in objective to keep quality, reduce losses, prolong shelf life and keep the price stable and ensure uniform providing of the onion bulbs during the year. Three different storage conditions were used namely, forced ventilated, natural ventilated and traditional storage systems. The considered parameters of the onion bulbs those to be studied are moisture loss, deterioration, sprouting and marketable percentage. The environmental factors such as temperature and relative humidity were recorded during storage. The results indicated that, the average temperature in center of onion pile   during the storage period ranged between 16.73 to 28.61 ˚C for the forced ventilated, where it was ranged between 18.18 to 31.03 ˚C for the natural ventilated, while in traditional storage system ranged between 19.52 to 32.93 ˚C. The bulbs stored under natural ventilated system showed the lowest moisture loss 2.83 %, and the lowest percentage of deterioration 6.55%, while lowest percentage of sprouting was recorded for the forced ventilated and natural ventilated systems 1.47 and 1.52%, respectively. The forced ventilated and natural ventilated storage systems recorded maximum marketable percentage (85.31 and 83.55% respectively), compared to traditional storage system (81.51%). According to above results, natural ventilated with perforated pipes can be recommended for local community, which assure simplicity and easy to apply.