Milk plays an important role in the human nutrition as an important protein and energy source. Β-casein is the most abundant casein fraction in the goat milk. The β-casein gene has at least 9 polymorphism in goat breed (A, A1, B, C, C1, D, E, 0 and 0’). The most important alleles are the zero (0) and zero’ (0’) alleles, because they decrease the quantity of β-casein protein in milk. The lower quantity of the β-casein changes the properties of the coagulation and the allergenin milk. This review is about the β-casein gene polymorphism in goat breed.