The silicon tracking system of CMS

The paper describes the large silicon tracking of CMS, one of the two general purpose detectors planned at the Large Hadron Collider of CERN. Ther system consits of three layers of silicon microstrip detectors instrumenting the interaction region as part of the Inner Tracking Detector of CMS. The expected performance of the system is discussed together with preliminary test beam results on single and double-sided prototype detectors.