Abstract: To estimate the selection effect and breeding potential of Bromus catharticus, 21 quantitative traits of 9 new strains and 2 varieties were used to calculate phenotypic coefficients of variation, genetic coefficient of variation, heritability and genetic improvement using analysis of variance, correlation analysis and cluster analysis. Analysis of variance showed that 17 traits reached significant among 11 accessions. Among them, 14 traits had a very high level of heritability; ranked (high to low) were dry matter yield, flag leaf sheath length, first leaf width, number of primary branches per panicle, penultimate leaf width, stem diameter, seed yield per plant, plant height and total number of flowers per panicle. The remaining 3 traits had medium or medium high heritability. Genetic analysis revealed that 11 traits had a high level of genetic improvement, including plant height, penultimate leaf sheath length, first leaf width, penultimate leaf width, stem diameter, tiller number, number of panicles per plant, spikelet number, number of primary branches per panicle, dry matter yield and seed yield per plant. Three traits, first internode length, flag leaf sheath length and number of florets per spikelet showed medium level of genetic improvement while flag leaf length and number of nodes per panicle showed low rates of improvement. Performance of the 9 new strains was generally better than the existing varieties, particularly in yield related traits including plant height, leaf size, stalk diameter, basal internode length, shoot number, dry matter yield and seed yield. Among the new strains, BCS1103 had the greatest plant height, dry matter yield and shoot numbers; BCS1106 possessed wide leaves, high shoot, panicle and spikelet numbers per plant, and high dry matter and seed yield; BCS1109 possessed the long basal internodes and leaf sheath, narrow leaves, thin stem, and high primary branche numbers. In the second group, B. catharticus cv. Qiannan showed better performances than B. catharticus cv. Jiangxia in yield related traits. We suggest that plant height, flag leaf width, tiller number, penultimate leaf width, stem diameter and number of panicles per plant are the most reliable traits when considering grass yield. When focusing on the grain yield, traits like tiller number, number of panicles per plant, dry matter yield and plant height might be more reliable and effective. The new prairie grass strains are likely to be released as new varieties due to their excellent performance.