Abstract: Taking Minqin oasis as a case, and by using geostatistics, RS, and GIS, this paper studied the spatial distribution pattern of soil dissolved inorganic carbon (SDIC) in 0-10 cm layer at watershed scale, aimed to understand the dynamic characteristics of SDIC under effects of water and soil in arid areas. In the oasis, the average content of SDIC in 0-10 cm layer was 0.056 g C·kg^-1, and the OneSample KolmogorovSmirnov (K-S) test showed that the SDIC content followed normal distribution, and the  spatial distribution of the SDIC could be best fitted by a linear model with the application of variation function. The research based on Kriging method showed that the SDIC content decreased gradually from south to north, being the highest in Baqu, the southeastern part of Minqin oasis, followed by in Quanshan, the central part of the oasis, and the lowest in Huqu, the northern part of the oasis. The landscape maps overlaid land-use types in the same periods showed that the SDIC content in the oasis was mainly ranged in 005-0.06 g C·kg^-1, being higher in cropland and sandy land, while lower in forest land, grassland, and saline land. Correlation analysis showed that the SDIC content was significantly positively correlated with HCO₃^- content, significantly negatively correlated with other salt ions and electrical conductivity, but weakly positively correlated with pH. This study could contribute to the understanding of the dynamic processes of surface soil carbon under effects of water and soil in arid-areas.

Key words: fate, analytical technique., AgNP, water environment, transformation