Abstract: The spatial correlation property of sea clutter amplitude and spectrum is researched with measured data according to the requirement of target detection problems under sea clutter.For the spatial correlation of amplitude,correlation coefficient and detrended fluctuation analysis methods are adopted.The research mainly concentrates on the trend of spatial correlation property with radar range resolution,sea state,sampling rate and integration in non-coherent condition,the property of real part,imaginary part as well as envelope of the correlation coefficient in coherent condition,and long range spatial correlation property in different sea states.Then,correlation coefficient and cross-correlation coefficient are used to quantify the spatial correlation of spectrum.The emphasis of this part includes the correlation property of single frequency component and the cross-correlation property between centroid,bandwidth and power level.The common tendency of spatial correlation property and the dependence of part property on both radar and environment parameters are mastered through the research,which can offer as prior information and theoretical reference for further understanding of sea surface scattering mechanism,optimum design of target detection algorithm as well as sea clutter simulation.