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Heqing basin is a typical dam agriculture area in Yunnan province in Southwest China, which was selected as the study area. 114 soil samples (0~10cm) were collected in metal cylinders (diameter 5cm; length 5cm), and soil bulk density (SBD) and soil water content (SWC) were measured gravimetrically. The classical statistical analysis methods of ordinary Kriging (OK) and ordinary Cokriging (OCK) were used to study the spatial variability of soil bulk density. Results showed that the values of soil bulk density ranged from 0.74g/cm3 to 1.60g/cm3, with an average of 1.25g/cm3. The low value of soil bulk density distributed in north and south regions in the study area, while the high value distributed in mid-east region, which were influenced by soil type, texture and land use in the dam area. Soil bulk density was highly correlated with soil water content and the correlation coefficient between them was -0.686. The spatial variability of soil bulk density was studied using OCK method with soil water content as auxiliary variable, and the prediction accuracy was enhanced by 36.61%.