INTRODUCTION: 1) In 1886, K. Eric Drexler first introduce the idea of using nanorobots for treatment of human body.2)Nanorobots are the nanotechnologically derived nanomachines which work at nano level in the body.3)These devices are ranging in size from 0.1-10 micrometer.4)The main element used will be carbon in the form of diamond nanocomposites because of the strength and chemical inertness of these form. COMPONENTS OF NANOROBOTS:The structure of nanorobot include 1)Payload 2)Micro-camera 3)Electrodes 4)Laser 5)Ultra-sonic signal generator 6)Swimming tail 7)Nanocomputer CATEGORIES OF NANOROBOT:1)Respirocytes : Artificial mechanical red blood cells, carry oxygen and carbon dioxide molecule.2)Clottocytes : Artificial platelets powered by serum-oxyglucose, reduce the clotting time & blood loss.3)Microbivore : Artificial white blood cell or nanorobotic Phagocytes spheroid device , traps blood pathogens breaks them 1000 times faster than white blood cell. APPLICATION OF NANOROBOT IN MEDICAL FIELD:1)BREAKING UP BLOOD CLOTS.2)FIGHT AGAINST CANCER.3)DRUG DELIVERY.4)NANOROBOTIC DENTIFRICES 5)DIAGNOSE DIABETES.6)BREAKING UP KIDNEY STONE.7)GOUT. ADVANTAGES AND DRAWBACKS: ADVANTAGES:1)Rapid elimination of disease. 2)Cost of surgery is low.3)No operation failure.4)Faster and more precious diagnosis. 5)No tissue injury or trauma. DRAWBACKS:1)Complicated maintenance. 2)Very costly for installation.3)Nanorobots should be programmed accurately otherwish may result harmful effect.