This study was carried out to determine the effects of different harvesting stage on nutritive value and the quality of ensiled kenaf after fermentation among six kenaf cultivars. Six kenaf cultivars including two different maturity groups, mid-late maturing (Auxu, Jangdae and Jinju) and early-maturing (Baekma, Jeokbong and C14), were planted on May 14, 2013. Four harvesting times were made at intervals of 20 days from 15 July to 16 September, 2013. In all cultivars, the CP (crude protein) contents were decreased by a delayed harvest; the CP contents of kenaf silage were ranged from 92 to 184 g kg-1. Interestingly, there were no significant difference of NDF (neutral detergent fiber) and ADF (acid detergent fiber) content between the cultivars, however NDF and ADF content of kenaf silage were significantly increased by a late harvest. The silages of all cultivars displayed a low pH ranges less than 4.0, which is sufficient for stable storage. The lactic acid contents in Auxu were from 2.57 to 3.21%, which is higher than other cultivars. The harvesting stages did not affect to the concentrations of butyric acid and acetic acid in all cultivars. These results indicate that the harvesting stage is more important for the quality of kenaf silage than cultivar differences. And kenaf silage could be also used as fodder for ruminants.