The study was conducted on the Evaluation of the chemical composition and biomass yield of selected forage species Napier (pennisetum purpureum) and Desho(pennisetum pedicellatum) grasses under irrigation condition in the LIVES project area.The field study was conducted in2017irrigation season at North Mecha district of northern Ethiopia. A total of 30 farmers (28 Napier producing farmersand2Deshoproducing farmers) were selected purposively. The selected respondents were interviewed using semi-structured questionnaire and both qualitative and quantitative survey method was used to collect the data. The collected data was analyzed by using descriptive statistics and Statistical Package for Social Sciences (SPSS) version 20.Thechemical analysis was conducted to determine the dry matter, chemical of the irrigation forage Desho and Napier grass).The result was indicated that, DM (92.48%), Ash (14.48%), OM(85.51%), N (1.96%), CP (12.29%), NDF (68.77%), ADF (45.43%) and ADL (4.97%) were investigated from Napier grass. Whereas (92.56%) DM, (12.95%) Ash, (88.78%) OM, (1.4%) N, (8.79%) CP, (74.36%) NDF, (45.93%) ADF and (4.99%) ADL were determined from Desho grass. The result indicates Napier grass had higher content of CP, CPY, Ash and, ADF, than Desho grass. However, DMY,and NDF contents of Desho grass were greater than Napier grass. On the other hand, the dry matter yield (DMY) of Napier and Desho grass was 6.89 t/ha and 8.48 t/ha, respectively. . This yield was lower as compared to the forage with better management and proper fertilizer uses. Hence, farmers were practiced proper use of fertilizer and management to improving the quality and the quantity of the dry matter yield (DMY) of Napier and Desho grass. Both of irrigation grasses have been an economic merit by serving as source of energy feeds especially for dairy cattle. Therefore, production of irrigated forage (Napier and Desho grass) is needed to improve the availability of livestock feed. Keywords: Chemical composition, dry matter yield, Napier and desho