Abstract body - Arabinoxylan (AX) in wheat flour is characterized by low content and high water absorption capacity, which competes for the water originally absorbed by starch and protein during the dough mixing process and affects the dough quality. The hydration characteristics of wheat AX itself and its competitive water uptake pattern with wheat protein and starch fractions are still unknown, and there is no clear range of specific water uptake for each fraction. In this research, we investigated the effect of fluorescent labeling on the structure, hydration and solution properties of AX, and analyzed the effects of AX on the water migration patterns of three different systems, namely protein, starch and flour, by using low-field nuclear magnetic resonance (LF-NMR), to quantitatively calculate the specific water uptake of each component in flour. The water changes in the wheat protein and starch systems caused by different molecular weight AXTF were linked to the water changes in the AXTF-flour system, and the proportionality of the water absorbed by each component in the flour was established to quantitatively calculate the specific amount of water absorbed by the proteins, starch and AX. In this study, the ranges of water absorption percentages of AX, protein, and starch were 4.467%-8.593%, 39.842%-45.995%, and 48.668%-52.609%, respectively. We elucidated the competitive water absorption mechanism, quantitatively analyzed the specific water absorption of AX, protein and starch during the dough-making process, and achieved the goal of quantitative evaluation of AX hydration properties