The CMS tracker

The tracker for the CMS detector at the LHC experiment will provide the possibility to both tag and reconstruct in detail b-jets and b-hadrons inside those jets. 15.148 silicon strip detectors and a pixel vertexing system allow secondary vertices to be found over the full CMS acceptance. This is necessary to study B-hadron physics including CP-violation, B s oscillations and rare B-decays right after the start of the experiment. After a more general description of the detector layout, expected results in terms of reconstruction capability with a special attention to vertexing and heavy flavor tagging are given