Mass spectrometry has been used as a useful tool to determine the degree of protein modification. In this study, the degree of phosphorylation between two materials, TaHAKAIR and TaHAKAIS, was identified by technique. There is a key amino acid variation in TaHAKAIR and TaHAKAIS. The phosphorylation level of TaHAKAIR and TaHAKAIS at this amino acid site was significantly changed by mass spectrometry, and the phosphorylation level of TaHAKAIR was the highest.