Abstract: This study aimed to assess the effects of different sowing dates on agronomic and biological yield of different maize varieties and to evaluate the correlation among biological yield and varieties,sowing dates and agronomic traits.Six maize varieties and four sowing dates were set to investigate the relationship between agronomic traits and biomass yield of varied maize varieties in different sowing dates.Among the selected varieties,three were silage-specific type and the others were dual-purpose(grain/feed)type.The results suggested that the agronomic traits of silage maize showed significant differences among different varieties and sowing dates(P<0.05),but there was no significant difference among individual sowing date or variety(P>0.05);the components of maize biomass yield were cutting plant weight,cutting straw weight,number of green leaves,ear position,plant height and ear weight,while there was a significant negative correlation between varieties and biomass yield.Yayu Silage No.8 was a suitable variety for planting in the low mountain plain region in southwest of Hubei Province and was recommended to be sowed in the late April.For the variety of Liyu 16,a great influence of different sowing dates on biological yield was observed:an advance in sowing date largely improved the biological yield,indicating that this variety had a certain application and promotion value as a dual-purpose maize variety of grain and feed.