This study examines the hypothesis that soil respiration fluxes are always positive, neglecting negative fluxes in arid regions that characterize more than 30% of Earth’s total land area. To cut down uncertainty, we focus on non-vegetated areas at a typical, large arid region (Central Asia). Soil respiration fluxes were reconciled as a direct sum of influxes (CO₂ fluxes entering soils) and effluxes (CO₂ fluxes released from soils). It was indicated that the annual average of effluxes was only 8% higher than that of influxes in 1979-2011. At typically alkaline sites (soil pH>9.5), extreme local annual average of soil respiration fluxes are negative. Therefore, negative soil respiration fluxes in arid regions are unneglectable. Although the soil respiration flux is useful as a measure of CO₂ effluxes from the soils and CO₂ influxes to the soils, its value as a measure of ecosystem processes is very much limited.