The myostatin (MSTN) gene is a negative regulator of animal muscle growth and development. This gene not only inhibits muscle cell growth and reduces fat accumulation but also exerts a significant effect on back fat thickness, birth weight and carcass traits. MSTN gene mutation, an important factor that influences economic traits, directly affects the growth and development of animals and consequently the quality of animal products. This paper reviews the structural and functional characteristics of the MSTN gene. The genetic variation of the MSTN gene is then compared among four domestic animals (cattle, sheep, goat and pig) and its correlation with important economic traits is analysed. The mechanism and structural characteristics of MSTN gene mutants are further discussed. This paper provides explication on the application of MSTN gene research in breeding and its importance to the advancement of animal husbandry.