Comparatively Lake Awassa is one of the most thoroughly studied lakes inrnEthiopia. However no attempt was made to bring the available informationrntogether in order to see the foodweb relationship in the ecosystem. Perhaps onern/rnof the plausible reasons for not modeling lakes till now is lack of comprehensivernand easy-to-use model. A friendly software model, Ecopath with Ecosim (EwE),rnwas constructed for Lake Awassa using different published and unpublished datarnthat were originally studied in the lake. Several parameters were also estimatedrnfrom the present study such as primary productivity, phytoplankton biomass,rnTilapia biomass and zoobenthos. The study was conducted between Novemberrn2003-August 2004. Thirteen functional groups including two ontogenic groupsrnwere used in the present analysis to see the trophic relationship and energy flow.rnThe results of the model give an overview of the resources found in the lakernsimultaneously and reveal the degree of interactions. The consumers are heavilyrnexploited in the system as shown by high ecotrophic efficiency while thernproducers including detritus are under exploited. Hence energy transfer fromrnlower trophic level seems very low. Flows from detritus were as important asrnflows from phytoplankton, designating the importance of both detritus andrn/.rngrazing food chain in the system. Mixed Trophic Impact (MTI) analyses indicaternthat phytoplankton and detritus have positive impact on most other groups. Onrnthe other hand, herbivore zooplankton and tilapia had negative impact onrnphytoplankton, the former being stronger. Lake Awassa has a low ecologicalrnefficiency with a value of 0.001. System primary production! respiration (P!R)rnratio of Lake Awassa is 9.844 showing the lake is at developmental stage or arnyoung ecosystem, warning that extra care should be given to humanrninterventions. However, since production is high the lake can contribute in thernfood self-sufficiency program of the country. This trophic model analysis alsornenables us to confirm the previous works and pinpoint the critical research gaps.rnProduction, biomass, mortality, feeding, reproduction etc for zoobenthos, Garra sp., Labeobarbus amphigrama and Ap/ocheilichtyes sp. are open to research.rnThe biomass, mortality etc of Labeobarbus intermidius should also be studied.rnKey words: Lake Awassa, Ecopath with Ecosim, modeling, trophicrninteraction, aquatic ecosystems