The spatial variation of oxidation-reduction regime was expressed through the soils disributed an different reliefs,at differnt heights of mountains,the soil types and utilizacioa patterns.The common characteristics of oxidation-reduction regime in soils can be summarized as follows:There was a well negative correlation berween Eh₇ (intensive factor) and the concentration of reducing substances (capacity factor) in paddy soils and natural soils,with the correlation coefficients -0.905 and -0.745 respectively,implying that the factors were different in signilicance but closely interrelated.The natural soils any upland soils befonged ro oxidzzing soils,having Eh₇ of 410-590 mV and concentration of reducing substances corresponding to 0.16-5.0×10^-5 mol/L of Mn²⁺,without strongly reducing subsaances.Whereas under different water conditions,the paddy soils had a wider range of oxidation-reduction regimes as compared with natural soils and upland soils,with Eh₇ of 400-(-20) mV and ttae amount of reducing substances of 1.3-17.8×10-5 mol/L of Mne²⁺,which was considered as a true synzboi for the former soils differeat from the latter.