The camera calibration is an important step towards structure from motion, automobile navigation and many other vision tasks. It mainly refers to the determination of camera intrinsic parameters, e.g. the focal lengths, the skew factor and the principal point. In practice, a good calibration algorithm should be robust, computational efficient and as convenient as possible for implementing. In this chapter, we first introduce the basic theory and methodology for determining camera intrinsic parameters. Then three different planar patterns are designed for camera calibration based on the theories. Finally, camera distortion correction is discussed. We will show that these approaches satisfy the above requirements. Besides those theoretic investigations, we have presented some examples and experimental results to demonstrate their applications.