Thirty four sorghum (S.bieolor (l).Moench) landraces consisting of 1020 indi vidual plantsrn(30 plants of each land race) collected from five agroecosites in North Shewa and SouthrnWela regions of Ethiopia (Bati 8, Fontenina 5, Hayike 2. Layignaw alaye 17, and MerewarnAdere 2) were lIsed in this study. The materials were classified on the basis ofrnadministrational zones (4 cl ass ifying variables; Woredas, ecosite of origin and altitudes,rnMorphological variation for the fourteen quali tative characters that showed two or morernphenotypic classes were estimated using the Shanonâ€¢Weaver diversity index (H').rnPhenotypic variation was found between and within each classifying variable. The value ofrnH' for ailiandraces varied from 0.32 to 0.98 with an overall mean of 0.77 Â± 0.04. One wayrnanalysis of variance (ANOVA) showed significant differences between characters withinrnall classifying variab les and this contributed to the largest portion of the total variance.rnCluster analysis based on ordinal variables grouped the landraces in 5 clusters. A higherrnproportion of landraces sharing similar altitude groups and similar agroecological sitesrnwere grouped together. Panicle compactness and shape as well as stalk juiciness were thernpredominant characters in grouping the land races into th ei r respective cl uster. Paniclerncompactness and shape also contributed relatively more to altitudinal and ecologicalrndi ffe rentiation. This differential distribution of different panic le types with respect torncompactness and shape revealed the adap tive significance o f panicle compactness andrnshape that re nected the patterns of di stribution of different races in north Shewa and southrnWelo regions. X2 test was carried out to detect the deviation of the observed rrequencyofrnall the characters from the expected ones. Significant dirferences were not observed forrnmost or the characters between the observed and expected rrequenc ies.rnIsozyme analysis was perfomled usmg two-enzyme systems esterase (EST) and acidrnphosphatase (ACP) to see the allelic variation among the 34 sorghum landraces. However,rnphenotypic polymorphism was not observed for any of the enzymes used in the analysis.rnFor the analysis of frequency of existence (diversity) of sorghum landraces under thernenvironmental variability (altitudes and field size), transect method over 100 plots (fields)rnwas used. As altitude levels increased or decreased beyond the range of 1500- 1650 m.a.s.l,rnthe diversity of tile sorghum land races also decreased. A relatively lower field size locatedrnnearer to the home range was found to contain higher diversity. The use values of the 34rnsorghum landraces were also analyzed by interviewing 30 informants in nonh Shewa andrnsouth Welo regions. Thirty informants were contacted and the uses of the identifiedrnsorghum landraces were recorded on 30 pl ots. Of atl the landraces zen gada and ahiyorncomprised the maximum number of uses (15 and 13, respectively). However, almost alt-30rnlandraces were known to have been selec ted for their nutritional value as injera makingrnand for their sui tability for beverage. Ethnobotanical survey was conducted and thernimportant data on fann er perceptions about the agromorphologica! traits distinguishingrnland races. cultural val ucs and prefcrred traits of sorghum landraces were coll ected.rnThe knowledge of farmers, which is documented in this study. is an important input to thernbuild ing up of the scient ific basis of ill-sil/l conservation of agrobiodiversi ty in sorghumrncrops. The information retained from the famlers' knowledge can also be applied in futurernbreeding activities and designingin-situ conservation program.