The objective of this work was to appraise the physiological quality of soybeans seeds since its R7 phase (30% moisture) for 21 days, in Capão do Leão, RS, Brazil, during the crop year 1991/92. The seeds were collected dailly and afler four months the physiological quality was determinated by germination, tetrazolium and accelerated aging tests. Germination took 12 days to begin decreasing its percentage falling from near 90% to 70% while vigor determined by tetrazolium decreased 1% per day and through the accelerated aging test it decresed 1,5% per day. The results allow to state that in regions, where strong dews occurr event under relative low temperature (20°C), seed deterioration can be easely detected since its R7 phase with more than 1% decrease on its performance per day.