Abstract: By means ot" analyzing many soil sample’s physical and chemical characteristic such as soil bulk density, non-capillary porosity,infiltration capability, soil organic matter, soil pH value and so on in different Quercus variabitis forest soil profiles, the results showed that they have obvious roomage variability. And this roomage variability in vertical is more than that in horizontal. Therefore, we must base on the deviation theory to confirm the soil sample in different soil depth. And this is the only way to ensure the results to be correct and comparability. The results also showed it is needed to sampling decades samples even more than 100 when analyzing infiltration capability, but less than 20 samples when analyzing other soil characteristic.