In China's Tibetan regions, there in history exist abundant customary laws that are strongly binding. The inherent customary laws such as Wergeld Norm still have an unthinkable influence on actual social life of Tibetan people. The mediation process of a case about accidental death caused by injury dispute in Guangming Village, Xiqing Town, Huangzhong County, Qinghai Province happening in July 2018, tells us the real performance of Tibetan customary law, which represents the vitality of traditional norms. That case is enlightening for us to understand the inheritance and think about the development of inherent customary laws. It also provides a vivid example for us to understand the rural governance under modern rule of law practice. In the dispute resolution process, rural cadres can refer to and even follow the inherent customary norms, in particular the good and procedural norms properly, on the basis of abiding by relevant state laws, so as to resolve disputes and social contradictions properly to restore rural social order and promote rural social development.