To determine whether supplementation of humate plus NaHCO3 amplifies the effects of their individual supplementation on egg production and quality during the late laying period, two hundred and forty Hisex Brown layers were assigned randomly to receive one of four diets containing no humate and NaHCO3, humate (0.1%), NaHCO3 (0.1%) or humate (0.1%)plus NaHCO3 (0.1%) from week 54 to 66. The experimental diets did not affect the mortality rate. As compared to control (un-supplemented) humate improved egg production, egg weight and feed conversion efficiency, whereas NaHCO3 alone or with humate increased feed intake and egg production. Egg quality parameters (specific gravity, shape index, shell stiffness, shell thickness, yolk colour, albumen index, yolk index and Haugh unit) were generally not affected by diet treatments except that NaHCO3 alone decreased albumen index and Haugh unit. It is concluded that Supplementation of humate or NaHCO3 improved laying performance at similar magnitude. However, their combination did not amplify their individual effects.