Abstract: Nonlinear filter for single passive sensor target tracking is studied in this paper, and the superiority and defect are compared and analysed. Gauss-Hermite filter is discussed detailedly. The particular method on Gaussian approximation of probability density function and Gauss-Hermite integral rule of different dimensionality are analysed qualitatively. Gauss-Hermite filter is an effective method for single passive sensor target tracking.