Low field nuclear magnetic resonance (NMR) technique was used to evaluate the capacity of NMR spectrometry in characterizing the different behaviors of water protons in navel orange during growth. Carr-Purcell-Meiboom-Gill (CPMG) sequence and mult-exponential regress model were used to calculate the spin-spin relaxation time (T2) of orange samples. Meanwhile, chemical properties (etc. total sugar, acid and solid content) were tested. Statistics analysis shows a correlation between chemical properties of orange and NMR relaxation time during growth, which indicate that interactions between molecules and water protons in orange are involved. Evaluating the behavior of liquid water by NMR shows a new view for better understanding the mechanisms of the macromolecular formation. Changes in NMR relaxation time parameters would be helpful for understanding the mechanism of decay and damage. Therefore, it would be helpful for finding a better food preserving method for the long term storage in the future.