本文采用扫描电镜和透射电镜对奥贝球铁组织形貌特征、组成相的分布进行了详细的观察与分析，发现贝氏体呈麦穗状，麦粒沿与麦穗长轴生长方向成６０°角平行生长，贝氏体内部由铁素体亚元组成，残余奥氏体呈条状或小块状相互连接，分布于贝氏体之间。不稳定奥氏体呈大块状，其内部是马氏体的形成源。 In this paper, scanning electron microscopy and transmission electron microscopy were used to observe and analyze the morphology and compositional distribution of the austenitic ductile iron. The results showed that the bainite was in the form of spikes, ° angle parallel growth, the bainite by the ferrite sub-element, the residual austenite was strip or small interconnected, distributed between bainite. Unstable austenite was massive, its internal source is the formation of martensite.