In this study, a two-year field experiment was conducted and the molar ratio of phytic acid/zinc was used to explore and assess the effects of zinc (Zn) fertilization on Zn bioavailability in wheat grains (Triticum aestivum Linn. cv. Yang Mai 16) by applying increasing rates of Zn fertilizers during the jointing stage. The results showed that Zn concentration in wheat grains was significantly increased while the molar ratio of phytic acid/Zn was significantly decreased with increasing rate of Zn fertilizer. Under 300 kg/hm² of ZnSO₄.7H₂O, Zn concentration in wheat grains was increased to over 60 mg/kg and the molar ratio of phytic acid/Zn decreased to below 15. It indicated that Zn bioavailability in wheat grains is significantly improved when wheat is fortified with Zn.