This study was carried out to investigate the effects of seeding dates on the growth characteristics, dry matter yield and mineral contents of rye cultivated in the paddy field. The field experiment was conceived as a randomized block design performed in triplicate with seeding dates of October 19 (T1), October (T2), November 2 (T3), November 9 (T4), and November 16 (T5). All treatments was harvested on May 22 of the following year. Plant length, stem diameter, dry matter yield, and total digestible nutrient (TDN) yield were higher in rye with early seeding dates (p<0.05), whereas TDN was higher with late seeding dates (p<0.05). There was no significant difference between crude protein and ether extract among the different seeding dates. Neutral detergent fiber (NDF) and acid detergent fiber (ADF) were higher with early seeding dates (p<0.05). K and Ca contents were significantly higher at T1 as compared to other treatments (T2, T3, T4 and T5). There was no significant difference in Mg and Na content among T1, T2, T3, T4 and T5 treatments. P content was higher in the order T1 > T2 > T3 > T4 > T5 (p<0.05). There was no significant difference in free sugar contents (glucose, fructose and sucrose) by treatments, whereas total free sugar content was the highest in T1 than in the other treatments (p<0.05). Collectively, the results obtained in this study indicate that it is favorable to seed (T1 and T2) soon after harvesting rice to increase dry matter, TDN yield and total free sugar content of rye in the midlands of Korea.