Wolfhart Pannenberg is one of the most distinguished German theologians during the late 20th century. He pays great attention to theological methods, especially anthropological-historical method in the early period and doctrinal method in the late. In Systematische Theologie, the Trinitarian God is one of the most important themes. This article explores the general thoughts of his Trinitarian God, including the starting points and roots as well as modalities in this study. At the same time, it reflects his critiques of Barth's subjective trinity in the background of the history of Trinitarian theology in the 20th century.