BACKGROUND: Seed aging is an important problem in developing countries which seeds stored in inappropriate condition. OBJECTIVES: Current research was carried out to study the effect of seed aging on quantitative parameters of wheat seeds (Chamran cultivar). METHODS: Experiment was carried out based on randomized complete block design (RCBD) with four replications. Treatment included seed aging factor at five levels (a1: zero or control, a2: 48, a3: 72, a4: 96, a5: 110 hr). RESULT: According to result of analysis of variance effect of different levels of seed aging on measured traits in the laboratory including the index of seedling emergence, mean daily germination, daily germination speed, seedling vigor, radicle length, plumule length, and seedling dry weight was not significant, but the effect of treatment on mean time for germination and coefficient velocity of germination was significant at 1% probability level. Mean comparison result of different level of seed aging indicated that the longest mean time of germination was related to the aging level of 110 hr (3.72) and the lowest one belonged to control treatment with aging level of 0 hr (3.25). Also the highest mean daily germination belonged to 100 hr seed aging level (10.55) and the lowest one belonged to the control treatment with 0 hr of aging (9.65). Moreover, the maximum and minimum amount of coefficient velocity of germination belonged to control (0.85) and treatment with 110 hr aging (0.55), respectively. CONCLUSION: Seed aging had significant effect on physiological indices especially on the mean time of germination and coefficient velocity of germination. Also temperature and duration of aging were the most important factors that affecting the occurrence and development of seed aging. Therefore, aging development by increasing temperature and its duration was predictable. Manuscript profile