Abstract
In this paper, 7 factors of river ecosystem are categorized from the view point of human impacts referring to Karr et al. (1986). The factors are 1) energy sauce ; 2) water quality ; 3) habitat quality ; 4) flow regime ; 5) sediment transport ; 6) biotic interaction ; and 7) human use.
Based on the review of targets of conservation and restoration of river environment, I proposed that the target of river restoration is to restore the equilibrium dynamic system to keep the function of habitat quality.
