In modern nanotechnology one of the most exciting area of research is the formation of nanoparticles through the biological interventions. Microbes and plants have inherent capacity to reduce metal through their specific metabolic pathway. In the present study Brassica juncea have been used to produce silver nanoparticles. Seedlings of B. juncea prepared in vitro and 14-days old plants were transferred into nutrient solution augmented with silver nitrate (25-2000 μM) allow the plants to grow in hydroponic culture for seven days. Then, the plants are harvested and analyzed through UV-VIS spectrophotometer and by Transmission Electron Microscopy (TEM) that confirms the nanoscale silver nanoparticles. We have found absorption peak in visible range (420-430 nm) of spectrum that is chiefly due to the silver nanoparticles. These biological synthesis methods considered as environmentally safe because of no toxic byproducts. Moreover, size of the nanoparticles can also be controlled by altering some conditions like pH, concentration of AgNO3 and temperature. Silver nanoparticles have large number of applications in non-linear optics, spectrally selective coating for solar energy absorption, biolabelling intercalation materials for electrical batteries, as optical receptors, catalyst in chemical reactions and as antibacterial capacities. So if these nanoparticles are synthesized by the biological methods, this would be more eco-friendly than the other common methods.