This paper is talking about an advanced augmented reality system for spinal surgeryassistance. Spinal diseases now have become gradually prevalent over the past two years. Andnow have an augmented reality-based system that to let the doctor able to see through thepatients anatomy thats call arcass system. Its using the proposed camera-projector systemoverlays preoperative 3d images into the patient.arcass system was tested on a preoperative 3d model dummy patient model andanimal cadaver model. During the test on dummy simulation arcass system shows the dummyand a spinal image projected onto the dorsal surface of the dummy. Next for the animal cadavertest it was performed on two pieces of pork and using real-time patient surgical procedures. First the ct images scanned and 3d modelling and labelling were performed using the visible patienttool. The arcass system performed well on dummy and animal cadaver experiments. Becausethe feasibility of the system has been demonstrated in real patients the trials have been acceptedby the institutional review board. The spinal specialists provided positive feedback on thearcass system.during minimally invasive procedures the doctor must track needles and other operativeinstruments. Navigation systems are complicated expensive and often require extra training.they sometimes need tracking devices which are them aggressive since they are fixing toinflexible body parts such as bones. Ar has been extensively researching for intraoperativevisualisation throughout the past years. In this technique real images are merged with computergraphics to enhance the multimedia information surrounding the user. Therefore spinalspecialists may be intraoperatively guided by projection-based ar techniques using preoperativect images of the patient. Compared to traditional laparoscopy ar systems offer an extendedfield of view multiple viewing directions flexible positioning of patients and less mismatchbetween the views of surgeon and instruments..however the arcass system contains some potential errors which may limit itsapplicability. First if the patients significantly alter their postures between ct scan and intra-operative surgery the projected spinal image may not satisfactorily map onto the body surface.second errors are inherent in both the camera calibration step and in manually selecting themarkers for image registration.