Abstract: Large-scale full-containment LNG storage tanks are extensively deployed in LNG terminals in China. This kind of storage tank contains two layers, inner tank (Ni9 steel) and outer tank (reinforced concrete), between which coldinsulating materials is filled. Such storage tanks need complex technologies for commissioning. Particularly, cooling is the most difficult-to-control factor with highest risks. Taking the whole cooling process of 3^# storage tank in Dalian LNG Terminal as an example, detailed description is made for the large-scale full-containment LNG storage tanks. In addition, relevant analyses and discussions are made by using the data. The paper summarizes experiences related to cooling and commissioning of large-scale LNG storage tanks, which may provide some guidance for improving and optimizing cooling and commissioning of LNG storage tanks.