This study was conducted to evaluate the nutritive value and the quality of ensiled kenaf after fermentation with three cultivars at three different times of harvesting. Experimental plot were allocated with three harvest date (Early;8/3, medium;8/15 and late;8/28) and three cultivars (Tainung-a, Everglade, Whitten). The DM (dry matter) yield increased with maturity in all three cultivars, especially in Whitten which showed the highest yield at each harvest time. The DM content in Whitten at late harvesting time was higher than other treatments (231 g $kg^{-1}$ DM). The CP (crude protein) contents of the kenaf silage of all three cultivars ranged from 151 to 164 g $kg^{-1}$. Highest content of NDF (neutral detergent fiber) was observed in Everglade at medium harvesting date, but the ADF (acid detergent fiber) content was highest in Everglade at early harvesting date (p<0.05). All treatments produced a pH less than 4.0, which is sufficient for stable storage. The pH of Tainung-a was higher than other cultivars at all harvesting times (p<0.05). Whitten showed the higher content of lactic acid (25.8 g $kg^{-1}$ DM) showed at early harvesting date than other cultivars (p<0.05), while the acetic acid content (21.1 g $kg^{-1}$ DM) was higher in Tainung-a at medium harvesting date (p<0.05). No significant difference was observed in ammonia-Nand butyric acid concentrations among all treatments. These results indicate that a kenaf silage could be used as fodder for ruminants. Especially, the Whitten harvested at late growing stage showed promise as a forage silage crop under Koran environments.