Abstract:In order to accurately determine δ13C values of the stable isotope13C-labeled wheat plant, this experiment studied the Element Analyzer-Isotope Ratio Mass Spectrometer (EA-IRMS) technology to determine the δ13C values of13C-labeled wheat plant. The results showed that the precision and accuracy of the results for the standard saccharose (IAEA-CH-6), standard wheat flour (OAS/Isotope) and the13C-labeled wheat samples were analyzed and all the standard deviations were less than 0.11‰. The stability of the EA-IRMS system were tested as well. The standard deviation of stability was 0.02‰. When the intensity of isotopic signal ranged from 1e-9 to 1e-8A, the linearity of EA-IRMS system was 0.003‰·nA-1. The δ13C values of wheat samples ranged from -25.25%~23.32%. This experiment provided reliably technological base for studying the distribution of photosynthetic products in wheat plants.