The present research had as its objective to evaluate the effectiveness of three conditioning methods of the physiological quality of soybean seeds (Glycine max (L). Merrill), cultivar FT-Estrela. Two seeds lots from the 1995/96 harvest, stored for five months in laboratory environment, were submitted to conditioning in a saturated atmosphere, substract soaked with water, and substrate soaked with polyethylene glycol 6000 (PEG) at 30%, for twelve conditioning periods (zero, 2, 4, 6, 8, 10, 12, 24, 36, 48, 60, and 72 hours) and evaluated after conditioning, after drying and after five months of storage. The evaluation of the physiological quality of the seeds was conducted through of germination and vigor test (first count of germination, the seedling lenght and accelerated aging tests). The soaking curves showed that the water absorption for the seeds was larger and faster in the method of soaking in water, followed by the conditioning methods with PEG and saturated atmosphere. The seeds, after the storage, developed seedlings with greater length. The conditioning, through the hydration in satured atmosphere, in substract soaking with water and in an osmotic agent (PEG 30%), followed by drying and storage, accelerated the germination, but it was not efficient in the increase the germination percentage and the vigor, when evaluated through the accelerated aging test.