Field experimentwas conducted in seasons 2006 and 2007 to evaluatethe response of soybean to different organic amendments under different tillage practices.  Organic amendments were, composted amendments Katamya plant residue compost (Kp), katamya city refused compost (Kc) and Kaha plant and cattle mixture compost (Km)) and animal manure (cattle (Cm), poultry (Pm) and goat (Gm)) and control (Control). The tillage treatments were, moldboard plow (MP); chiselplow (CT), and no-tillage (NT). Tillage treatments significantly increased soybean yield compared to the control. In growing seasons, soybean plant growth, yield components and the yield increased under CT followed by MP and NT compared to control. Amended CT and MP increased average yield in both season over NT by 23.0 and 19.0%, respectively. No significant difference in soybeanyield was found between CT and MP under both amended and non-amended treatments. However, a significant difference between NT and both CT and MP was found. Across all the tillage treatments, compost amendments increased soybean growth, yield and yield components compared to animal manure. Among compost amendments, amended treatments with Kc produced the highest plant growth, yield components and yield followed by Kp and Km, respectively. While, among animal manure, Cm and Pm treatments significantly increased plant growth, yield components and seed yield as compared to Gm treatments. The results also show that, protein percentage increased with amended treatments by both compost and animal manure. Alternatively, oil content % increased with non-amended treatments. The average of seed protein obtained under CT, MP and NT with compost amendments, increased by 7.0%, 8.0% and 3.0% while, the increase with animal manure was 3.0%, 4.0% and 2.0%, respectively over the control. A significant difference in seed content of N and K was found between composted and animal manure treatments under CT and MP systems. Under NT the difference in NPK between composted and animal manure treatments was not significant. The applied organic amendments influenced growth, seed yield and its components, seed protein and oil content of soybean.