Foxtail millet (Setaria italica. L) is a vital crop that plants as food and fodder crop, with strong stress resistance and bundle of nutritional elements. Selenium (Se) is a component essential for human and animal cells, beneficial for plants growth and quality improvement. This study attempts to explore the ability of Se-responsive in foxtail millet and establish a corresponding evaluation system. We conducted the correlation analysis and principle component analysis based on 11 phenotypic indicators, including seedling height, leaf area, stem thickness, fresh weight of shoot, fresh weight of root, root length, total root length, root volume, apical number, shoot and root selenium content in 205 foxtail millet germplasm accessions. The membership function method was used to comprehensively evaluate the selenium responsiveness, and identify the genotypes showing Se efficient and Se deficient at the seedling stage. Furthermore, the enzymatic activities of superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) in shoot were analyzed between Se efficient and deficient varieties. 205 foxtail millet varieties were grouped into five categories. There were 30 high Se-efficient responsiveness accessions, 49, 40 and 32 with medium Se-efficient responsiveness accessions and 54 deficient accessions. Under 0.5 mmol.L-1 Se treatment, the activities of SOD and POD were increased, whereas the activity of CAT was decreased. Collectively, the comprehensive index is more objective to evaluate the selenium efficient utilization of foxtail millet at the seedling stage, and the antioxidant enzymes activities of the plant are important for the responsiveness of foxtail millet to the Se treatment.