Peat bogs have seriously degraded due to global change and human disturbance and overgrazing of pastures in Gahai wetlands of Gansu Province. Using an approach of spatial sequence instead of temporal sequence, the investigations were conducted at four different degradation stages of peat bogs to find out the changing trends of soil properties and water conservation functions during the peat bogs degradation. The results showed: With the increase of peat bogs degradation gradient, 1) the average soil bulk density in 0-40 cm soil layers increased continuously, soil total porosity decreased gradually, and they both changed in different soil profiles. 2)The value of soil chemical properties containing the soil organic matter, total nitrogen (TN), available potassium (AK) and hydrolysis nitrogen (HN) decreased gradually, ammonium nitrogen (AN) increased gradually, the contents of total phosphorus and total potassium had no definite trend, whereas they were fluctuating changes along the soil profiles. 3) The highest contents of soil natural moisture, minimum storage and capillary storage were found in the non-de-graded peat bogs, while the lowest were the middle-degraded. The results of variance analysis showed that the soil bulk density, total porosity, organic matter, AN and water storage capacity had significant differences among different degradation stages (P<0.05). The soil saturated storage and capillary storage were positively correlated with the soil organic material content (P<0.05), as well as influenced by plant coverage and depth of peat soil indirectly. These results indicated that the basically reasons for changes of soil properties and water conservation function among degradation process of Gahai peat bogs were the draw down of groundwater and the decreases of plant coverage, soil organic material and peat soil depth.