Abstract: As the increasing of radar resolution, the statistics of the clutter appear no longer to be Gaussian. This paper derives a covariance matrix structure of sea-clutter from maximal likelihood function of probability denisty function of no-Gaussian sea clutter. Initialization of a Toeplitz matrix of fixed point covariance matrix in no-Gaussian sea clutter is proposed by slove the covariance matrix. The simulation result shows that the proposed method can enhance the detector performance in real sea clutter.