This paper is elaborated in order to estimate suspended sediment in Isser watershed located in North-West of Algeria. Power functions models by least squares regression were developed to establish rating curves. 2026 pairs of instantaneous water discharge (Q) and instantaneous suspended sediment concentration (C) from the period 1988-1989 to 2003-2004 were used. In order to reveal the temporal impact, four subdivision data are elaborated: all, annual, seasonal and monthly scales. Better estimation of the total suspended sediment yield is obtained by application of the power linear model in monthly division data (-0.16%). when considering efficiency, both models with seasonal scale offered coefficients in order of 0.95%. The approach of correction for models did not improve accuracy of the estimation. The results have indicated for the 16 years of the available data, that the Isser watershed has drained a total of 194.37 million m3 of water and 1.4 million tons of suspended sediments, with a specific degradation of 77 tons/km²/year.