The article reviews the role of Hedgehog (Hh) signaling in animal development, focusing on its functions in *Drosophila* and vertebrates. Hh proteins are key mediators of fundamental processes such as growth, patterning, and morphogenesis in various regions of the body plans of vertebrates and insects. They act as morphogens, mitogens, and inducing factors, regulating cell fate, proliferation, and organ form. The review highlights the conservation of Hh signaling across different species and its diverse roles in embryonic development. Key findings include the identification of Hh genes in *Drosophila* and their subsequent discovery in vertebrates, the role of Hh in segment polarity and neural tube patterning, and the involvement of Hh in limb development. The article also discusses the mechanisms of Hh signal generation, reception, and transduction, including the roles of Ptc and Smo proteins. The review emphasizes the importance of Hh signaling in maintaining proper cell identity and tissue architecture, and the potential implications of Hh signaling失调 in diseases such as holoprosencephaly.The article reviews the role of Hedgehog (Hh) signaling in animal development, focusing on its functions in *Drosophila* and vertebrates. Hh proteins are key mediators of fundamental processes such as growth, patterning, and morphogenesis in various regions of the body plans of vertebrates and insects. They act as morphogens, mitogens, and inducing factors, regulating cell fate, proliferation, and organ form. The review highlights the conservation of Hh signaling across different species and its diverse roles in embryonic development. Key findings include the identification of Hh genes in *Drosophila* and their subsequent discovery in vertebrates, the role of Hh in segment polarity and neural tube patterning, and the involvement of Hh in limb development. The article also discusses the mechanisms of Hh signal generation, reception, and transduction, including the roles of Ptc and Smo proteins. The review emphasizes the importance of Hh signaling in maintaining proper cell identity and tissue architecture, and the potential implications of Hh signaling失调 in diseases such as holoprosencephaly.