The experiment was conducted to evaluate the effect of fertilizer type and harvesting age on botanical composition , forage yield and chemical composition of natural pasture in North Mecha district Northwestern, Ethiopia. The experiment was laid out in a 2×4 factorial arrangement in a randomized complete block design with 5 replications giving a total of 40 plots, each measuring 2×3 m2. The spacing between plots and block were 1m. The treatment consisted of four types of fertilizer application: urea fertilizer (100kg), compost (7.5 ton), mixture of urea and manure (50kg urea and 3.75 ton) and no fertilizer as control compared at harvesting 90 and 120 days of harvesting age. Samples were harvested for forage yield and chemical composition evaluation at both ages. Dry matter, crude protein Ash, neutral detergent fiber, acid detergent fiber and lignin were determined using the established standard laboratory methods. All data were subjected to GLM ANOVA procedures of SAS version 9.0 and descriptive statistical analysis was also employed for percentages of the different species. The botanical composition of the natural pasture that has been identified at the experimental site included five grasses (Setaria pallidefusca, Eleusine flocci folia, Cynodon dactylon (L.) Pers, Panicum Coloratuum, and Pennisetum macro rum Trin), one legumes (Trifolium decorumchivo) and one other forbs (Cyperus esculantus) belonging to different families. Identification of all species was undertaken in the field together with livestock keeper. The result indicated that forage dry mater yield botanical composition interaction were significantly affected (p < 0.001) by fertilizer type and harvesting age. The highest botanical composition of grass was recorded with urea fertilizer (82.16%) at 120 days while highest legume component was recorded with compost fertilizer application (82.90%) at 90 days. Higher forbs (0.66 %) were found in control plot at 90 days. Urea fertilizer at 120 days of harvesting age resulted in highest forage DM yield (8.26 t/ha) while the lowest DM yield (3.20 t/ha) was recorded from the control in both harvesting