Abstract: In order to understand the structural characteristics of soil inorganic nitrogen in natural secondary Picea asperata pure forest, this study took Luya Mountain typical natural secondary P.asperata pure forest in North China as research object. Based on the theory and method of geostatistics, small-scale spatial heterogeneity of soil nitrate nitrogen and ammonium nitrogen content of P.asperata pure forest at the same elevation in Luya Mountain was analyzed. Results showed that variable coefficient of soil nitrate nitrogen and ammonium nitrogen was strong in plot 1 because of microrelief. The coefficient of variation of soil nitrate nitrogen and ammonium nitrogen in plot 2 and plot 3 was moderate variation. Soil heterogeneity of ammonium nitrogen was higher than nitrate nitrogen. The content of soil ammonium nitrogen in all plots and soil nitrate nitrogen in plot 1 showed spatial auto-correlated variation in the whole range of the research area. The content of soil nitrate nitrogen showed a smaller scale spatial auto-correlated variation in plot 2 and plot 3.