Abstract: The study uses field investigation and laboratory analysis methods to analyze oak woodland soil layer characteristics and the occurrence of soil organic carbon density characteristics and the occurrence of layer effects on organic carbon density.The following conclusions are:1) With increasing altitude,oak woodland soil layer distribution occurs significantly,and the outside layer of soil genesis climate impact Zunyi and Tongren increases significantly;2) With the increase of soil depth,organic carbon content in Zunyi and Tongren shows a downward trend,showing a rising trend in soil bulk density and organic carbon density fluctuation is violent in Zunyi ;southwestern Guizhou Qiannan organic carbon density changes and trends are complicated,soil bulk density changes are in the rise;3) With sea level rise,organic carbon density is in the overall upward trend,which in southwest Guizhou plot altitude,soil organic carbon density was the lowest;Zunyi plots are at highest elevation,and soil organic carbon density maximum;4) Pearson index and significant index research shows that oak woodland organic carbon density generating layer of soil showed some correlation,but the correlation was not significant.

Key words: oak woodland, soil forming layer, organic carbon density, Guizhou Province