The glossy leaf is a genetic trait that showed pleiotropic effects on disease and pest resistances as well as being a varietal marker in Brassica oleracea and Zea mays. The author aimed to clarify the genetic characteristics of glossiness that were newly found in sorghum leaves. The F₁, F₂ and F₃ populations derived from two crosses of (g × G) were evaluated for leaf glossiness by spraying water. Since the expected ratios of (g : G = 1 : 3) were well fitted in the segregations of F₂ and F₃ populations, a single recessive factor for the control of glossy (g) was confirmed, and the symbols gl and Gl were tentatively assigned for g and G. The F₄ lines with gl and Gl derived from two crosses of (g × G) were examined for pleiotropic effects on leaf digestion and leaf blight resistance. The 23 F₁ and F₂ between 7 varieties having non-glossy (G), glossy (g) and true-glossy (tg) phenotypes were evaluated for leaf glossiness by spraying water. The phenotypes of F₁ were tg in (tg × tg), g in (tg × g) and (g × g), and G in (tg × G) and (g × G). The expected ratios of (tg : g = 1 : 3), (tg : G = 1 : 3) and (g : G = 1 : 3) in F₂ segregations were fitted well. The results suggested that tg, g and G were multiple alleles located in a glossy locus. Consequently, the symbols gl¹, gl² and gl⁺ were proposed to denote the multiple alleles for g, tg and G in the glossy locus, respectively.