Abstarct: Seed decay is one of the consequences of reduced seedling growth that leads to reduction in the power plant competition, uses of environmental facilities and tolerance to adverse environmental conditions and the damage to farmers, So should look for solutions to increase the efficiency of the decayed seeds during periods of our warehouse. In order to evaluate the effect of pyridoxine on soybean plant characteristics due to decayed seeds in weed stress conditions, The experimental was performed factorial on the basis of a randomized complete block design with with three replication was done at at the university of shahrood in 2015. experimental treatments were two levels of weed (non-weeding and weed), seed decay at three levels (zero, 70 and 90 hours) and the pre-treatment were with pyridoxine in three levels (zero, 0.02 and 0.04 percent). Deterioration of soybean seeds were during 70 and 90 hours at high humidity and a temperature of 40˚C. duration of pre-treatment with pyridoxine levels Was in 6 hours. The results showed that non-weeding of weeds and also increase the degree of deterioration decreased dry weight of leaf, stem and pod, number of pod per plant, number of seed per pod , seed yield, Chlorophyll a and b, carotenoid, catalase and ascorbate peroxidase activity, Percent and oil yield, Percent and protein yield, Soluble sugars and leaf area index. increasing in the degree of seed deterioration decreased peroxidase enzyme as well as other enzymes. Seeds pre-treatment with pyridoxine especially the concentration of 0.02 percent increased significantly in the most treatment such as dry weight of leaves, stem, number of pod per plant, number of seed per pod , seed yield, Chlorophyll a and b, carotenoid, catalase, ascorbate peroxidase , oil yield, Percentage and protein yield were followed. Pyridoxine had not a significant effect on deteriorated seeds of soybean. According to the results, the seeds of deterioration were less able In competition with weeds that finally caused the a significant reduction in seed yield. Of course the use of concentration of 0.02 percent of pyridoxine in these situations was improved growth and yield parameters. So in total, This concentration of pyridoxine could be introduced the most effective concentration in the weeding and non-weeding conditions in the range of the experiment.