Maranta arundinaecea is otherwise known as arrowroot. It promotes weight loss, treats diahorrea and stimulates the immune system. As Arrowroot is rich in starch, it helps in good digestion by mild laxative in regulating the bowel movement. Also it reduces stomach pain and bloating. Selenium is a semi conductor so it is used in making electrical wires. It is used in potent chemotherapy. It is an anti-cancer agent due to its invasion of apoptotic pathway and cell cycle arrest. Usually the arrow root extract is available as powder. The powder is diluted and mixed into sodium selenite solution and this combination is observed for 3 days. After 3 days, it is centrifuged and collected in a pellet form. The lactobacillus and streptococcus mutants are used for culture of organism for 1 day. The extract is tested for for anti-bacterial activity. Result- It shows the sector where it can inhibit in Streptococcus mutans and lactobacillus. Maranta arundinaecea root mediated selenium nanoparticles shows very good antibacterial activity will used in many biomedical applications is future.