Based on the geometrical property of the vanish points determined by two perpendicular groups of parallel lines,a self-calibration approach was proposed to calibrate the camera′s intrinsic and extrinsic parameters. Some constraints on the intrinsic parameters were established via the perpendicular property of the vectors,which connect the optical center and the vanish points. These constraints can be solved linearly by using variable substitute. Aiming at determination of the lens distortion coefficient,a nonlinear optimization approach,based on nelder-mead simplex algorithm,was proposed when the center to center distance between adjacent sensor elements is known. The intrinsic parameters obtained by the linear approach can be used as the initial value of the nonlinear optimization algorithm. The extrinsic parameters were obtained by establishing a transitional coordinate system. The approaches proposed in this paper do not need the actual coordinate of the calibration points. Extensive simulations and experimental results with real images show that these proposed approaches are both accurate and robust.