Abstract:In order to compare the differences between various methods in determining soil respiration as well as its 13C isotope, gas chromatograph (GC-TCD), stable isotope mass spectrometer (Gasbench-IRMS), cresol red coloration (MicroResp) and alkali absorption were applied to measure soil respiration rates, two methods that Gasbench-IRMS andalkali absorption were used to detect 13C isotope abundance in soil respiration, so as to accurately assess soil respiration and carbon emissions, and provide reference for related research. The results show that: 1) Soil CO2 emission rates measured by the two instrumental methods (GC and IRMS) are analogical (basal respiration) or trend-consistent (induced respiration), with good repeatability (standard deviation is 0.011, 0.010 mg /(kg·h), respectively) and high accuracy. The data from MicroResp is similar to that from apparatus, but the precision is relatively poor. Partial results determined through alkali absorption method are either higher (soils with low SOM content) or lower (soils with high SOM content) than the real values. 2) In the detection of 13CO2 abundance, the deviation determined by Gasbench-IRMS is small (standard deviation of the δ13C value is 0.137‰), and the results is closed to the expected values, can accurately reflect the utilization of surrounding substrate by soil microbes during respiration. In conclusion, the instrumental method can more accurately determine soil respiration and its 13C isotope than chemical analysis methods (MicroResp and alkali absorption).