Red light significantly affects the expression of plant photoreceptor genes and influences stomatal development through crosstalk of the constitutive photomorphogenic 1–cryptochrome–phytochrome signaling pathway. When blue light was replaced with red light, the expression levels of ZmCry1, ZmPhyB1, ZmEPF2, and ZmEPFL9 were enhanced, whereas that of ZmCOP1 was restricted. Moreover, the expression levels of ZmSPCH and ZmMUTE were also enhanced, but they were generally lower than those under white light. Consequently, stomatal formation, which was determined by net photosynthesis, stomatal conductance, intercellular CO₂ concentration, and transpiration rate, was inhibited through decreased stomatal index and stomatal density. We conclude that red light positively regulates EPFL9 in the intercellular signaling but reduces the positive regulation of blue light on COP1 and epidermal patterning factor 2 in the intracellular and intercellular signaling; therefore, though red light promotes the gene’s function on stomatal development of seedling maize, blue light maybe dominant to red light in seedling stage.