Ten strains of Bradyrhizobium japonicum were evaluated in an acid soil (incepticol) to assess nodulation and their impact on N-assimilation and uptake by plants, dry matter and grain yield of soyabean.Strains MB2P3, MB2P3 MB2P2 and MB2D1, MB2D2 and MB2D3 have been found promising with respect to have higher efficiency in acid soil. Among promising strains, ~ain MB2P3 was superior with respect to nodulation behaviour, recorded highest nodule nwnber and their dry weight, N assimilation and uptake by plants at 45 days after sowing as well as at 50% flowering (75DAS) stages. Highest grain yield of soyabean was recorded with the same strain MB2P3. Assimilation and uptake of dry matter and grain yield were significantly and positively correlated with nodule number and dry weight thereby clearly indicated an increase in production in acid soil as a result of strain inoculation. The relative effectiveness of individual strains in terms of N-uptake was recorded highest by strains MB2P3 followed by MB2D3 and MB2Dl Relative effectiveness of various strains followed the order as: MB2P3 > MB2D3 > MB2D1 = MB2P2 = MB2Pl = MB2P2 = MB2 Ref-1> MB2BG-l > MB2Bj-l > MB2 Sehore-l.