Effects of different Aspergillus niger strains on main nutritional components of grape seed insolid-state fermentation were investigated in this study. Grape seeds were fermented with threedifferent A. niger strains which are ATCC 9142, ATCC 200345 and ATCC 52172. Fermentedand unfermented grape seeds were analyzed for crude protein, ether extract, ash, crude fiber,neutral detergent fiber (NDF), and acid detergent fiber (ADF). Unfermented grape seeds (controlgroup) and fermented groups: FG1 (ATCC 9142), FG2 (ATCC 200345) and FG3 (ATCC 52172)were compared each other depending on the results of chemical analyses. Crude proteinincreased (p < 0.001) with fermentation in all groups and the highest increases were observed inFG2 and FG3 groups. Ether extract was similar with control in FG1 group but decreased (p <0.001) in FG2 and FG3 groups. Ash content increased (p < 0.001) through fermentation in allgroups, the highest increases were noted in FG2 and FG3 groups. Crude fiber, ADF, NDF andnitrogen-free extracts (NFE) were decreased with fermentation in all groups (p < 0.001).Whereas the highest decreases of NFE were observed in FG1 and FG2 groups, the highestreduction in crude fiber, ADF and NDF were ocurred in FG2 group. These results showed thatnutritional quality of grape seeds can be improved by A. niger solid-state fermentation and thebest results were taken from ATCC 52172.