The present study deals with the impact of selenium nanoparticles on growth, biochemical characteristics and yield of Cluster bean Cyamopsis tetragonoloba grown for a period 60 days Sodium selenite and ascorbic acid was utilized for the synthesis of Selenium nanoparticles using precipitation method. Selenium nanoparticles were characterized by using SEM, EDAX, FTIR and XRD. Pot culture studies of cluster bean in different quantity of Selenium nanoparticles such as 0,100, 200, 300, 400 and 500mg for treatment T0 (Control) T1, T2, T3, T4 and T5 and growth biochemical and yield were estimated at the end of 60 days. SEM image of selenium nanoparticles was observed as spherical in shape. EDAX spectrum recorded on purity of selenium nanoparticles. The FTIR spectrum of selenium nanoparticles was analyzed in the range of 4000-400 cm-1 spectral bands were observed. The germination percentage in T0, T1, T2, T3, T4 and T5 are 100,90,80,90,100 and 100 respectively. Among the treatments the shoot length is higher (21.8) in T1 containing 100mg of selenium nanoparticles and lower in(12.01) T5 containing 500mg of nanoparticles. Root length, fresh and dry weight and leaf area were higher in T2. The vigor index is higher T4.The chlorophyll a, b total Chlorophyll, carotenoids, anthocyanin, protein, L-proline, free amino acids and leaf nitrate were higher inT4.Among the treatments yield of cluster bean is higher in T4 and lower in T0.