About ten years ago, the long-have-been neglected region in carbon cycle study, the desert region, started to get attentions, as several studies indicated that this was a huge potential carbon sink. The sparse vegetation and poor humus in desert soil made the inorganic carbon in desert soil the first candidate for seeking carbon sink. The following studies revealed that the dissolved inorganic carbon (DIC) is of atmospheric origin, and is an active participant in modern carbon cycle. Diurnal temperature variation changes the solubility of CO₂in soil water, which in turn created an “inorganic respiration” in the soil with CO₂ pumped day-in/night-out. Extra irrigation, aimed at washing salt out of the soil in the largely saline/alkaline arid region, also washed the DIC out of the soil and forms a carbon sink in the groundwater. Studies thus far still can not prove that carbonates in the soil is an active player in modern carbon cycle, but can prove that in the desert soil with weak biotic processes, abiotic process may not only dominate CO₂ exchange between soil and atmosphere, but also create carbon sink of inorganic nature.