Macro_ invertebrates are good indicators of human land use impacts because they arernsensitive to habitat alterations. The present study aimed at assessing the ecological impacts ofrnsediment loading on macro-invertebrates with the view to develop sediment sensitiverninvertebrate index (PSI) along the gradient of Awash River, Ethiopia. Three sampling sitesrnwere selected along the gradient of Awash River for evaluation of physicochemicalrnparameters, soil particle size, organic matter and determination of the richness and diversityrnof macro-invertebrates. Macro_ invertebrates were collected using standard dip net based onrnRapid Bio Assessment Protocols for use in streams and wadeable rivers from the same kindsrnof microhabitats (pools and vegetated areas)and identified to the family level. Alongside, onrnsite of measurement of Physico chemical parameters (To,DO,pH and Conductivity ) wererntaken. The results indicated that concentrations of dissolved oxygen, temperature, pH,rnconductivity, Nitrite and Nitrate showed significant difference among samplingsitesrn(ANOVA),(P< 0.05). The percentage abundance of families of macro_ invertebrates wasrndetermined from all sites. Total of 19 families comprising 7,094 individuals were identifiedrnfrom all the sites. The sediment sensitivity result indicated that site one (S1)was moderatelyrnsedimented and had the highest family richness, while site three (S3) was heavily sedimentedrnwith the least family richness. Macro_ invertebrate which indicated moderately sedimentedrnsites are Baetidae and Lepidostomatidae whereas for heavily sedimated site Hydrophilidaernand Lymnaeidae were dominant. The study indicated significant effect of different levels ofrnsedimentation on macro-invertebrate community structure.As the sediment emanated from therndegraded Awash catchment, there is need toprevent and control the ever-increasingrndegradation of the water quality of this ecologically and economically important river.rnKey words: Awash River, Bio indicators, Macro _invertebrate, PSI; RDA, Sedimentation.