Soil samples,collected from farmlands and woodlands in different areas of the Loess Plateau,were incubated aerobically in the lab for 35 days. Results show that the concentration of soluble organic carbon(SOC)in the samples decreased, while the concentration of soluble organic nitrogen(SON)increased significantly during incubation. Typ-Eum-Orthic Anthrosols was much higher than Typic Hapli-Ustic Argosols and Typ-Isohumosols in SOC and SON at the beginning of and throughout the incubation. In the case of Typ-Ishumisols,woodland was significantly higher than farmland in SOC and SON. Incubation significantly increased UV-80 and HIX_em values of soluble organic matter. The rising trend of the latter was especially significant on the 8th day and the 35th day. The SOC/SON ratio of the samples gradually declined with the incubation going on. It was discovered through correlation analysis that the increase in UV-80 value was positively correlated with the decrease in SOC on the 35th day, and that remarkable negative relationship between initial HIX_em and the decrease in SOC on the 8th day,which suggests that UV-80 and HIX_em are suitable indicators that may to a certain extent reflect changes in types and structures of SOM in the soil.