This paper investigated the effects of L-lysine (Lys) and L-arginine (Arg) on the water-holding capacity (WHC) and hardness of myosin gel as well as the mechanism of these effects. The results showed that Lys, Arg, and KOH increased the WHC but decreased the hardness in all cases. At pH 6.32, the WHC increased in the order control < KOH < Lys ≈ Arg, while the hardness decreased in the order control > KOH > Lys > Arg. Lys shortened low field nuclear magnetic resonance spin-spin relaxation times (T 2 ), while Arg and KOH slightly affected T 2 . Lys, Arg, and KOH had different influences on the molecular forces in myosin gels and the distribution of myosin size. Lys formed a gel with porous clusters, while Arg generated a gel with fine caves. Therefore, both Lys and Arg changed the microstructure of myosin gel by changing the distribution of the myosin size as well as the molecular forces that form and/or maintain myosin gel, ultimately contributing to the differences in the WHC, hardness, and T 2 .ARTICLE HISTORY