Grassland ecosystem is one of the most important terrestrial ecosystems and plays a critical role in global carbon cycle.However,compared with other ecosystems,studies of carbon tock in grassland ecosystem,especially in the Loess Plateau were relatively less.Shrubs are the dominant plant life form in Loess Plateau,Northern China.Based on the continuous measurement of soil respiration and net ecosystems CO₂ exchange rate within and outside of the Artemisia gmelinii shrub patch in the grassland of Loess Plateau by using closed chamber method in the growing season of 2012,the temporal variations of soil respiration and net ecosystems CO₂ exchange were studied with the effects of temperature and soil water content.The results are as follows:(1)The diurnal variation of soil respiration rate both within and outside of the shrub patch showed an asymmetric single-peak pattern,while that of net ecosystems CO₂ exchange rate both showed sigmoid curve under normal circumstances and “twin peaks” type with the water deficit.The peak values of soil respiration rate appear in August while net ecosystems CO₂ exchange rate in September.(2)The daily averages of soil respiration and net ecosystems CO₂ exchange rate within the shrub patch are significantly higher than that outside.The averages of soil respiration rate within and outside of shrub patch in the growing season are 5.49 and 2.93 g·m^-2·d^-1,respectively,and are close to the observed value in May.(3)The averages of net ecosystems CO₂ exchange rate within and outside of shrub patch in the growing season are -3.86 and -1.19 g·m^-2·d^-1,close to that observed in May and July,respectively.“fertile island” is observed under the shrub,which can contribute to the carbon accumulation in this region.Soil moisture and soil temperature are the key factors controlling the variation of soil respiration rate,both within and outside of shrub patch,while net ecosystems CO₂ exchange rate was mainly controlled by soil moisture.