Abstract: Graphite-like C₃N₄ (g-C₃N₄) is ané cient visible-light-driven photocatalyst which is com-monly used in pollutant degradation. The photoreactivity of g-C₃N₄ depends on the prepa-ration conditions to a large extent. In this work, we linked the preparation conditions of g-C₃N₄ to its stability and photocatalytic activity through dye photodegradation experi-ments and sensitivity mathematical analyses. The sensitivity mathematical analyses show that the effect of calcination temperature is more significant than calcination time on the photoreactivity of g-C₃N₄. The photocatalytic activity of optimized g-C₃N₄ in rhodamine B (RhB) degradation under visible light was 100 times higher than that of non-optimized one. The enhanced performance can be attributed to the increased specific surface area of g-C₃N₄ and the increased migration velocity of photogenerated electron-hole pairs on the surface. This work deepens the understanding of the relation between preparation conditions and the charateristics of g-C₃N₄, and provides an extremely simple method for significantly improving the photoreactivity of g-C₃N₄.