A review. Quartz crystal microbalance (QCM) has many advantages in research, but the data interpretation has hindered its applications in many research fields, especially for application in liquid Recently, we proposed'solidified liquid layer' (SLL) model to simplify the data anal. In this article, some missing evidences are provided to demonstrate the SLL model. The thickness result from ellipsometry accords with the result from the SLL model. The SLL model predicts that 1 Hz signal respond to a 0.18-nm change of TSLL, which greatly improve the resolution of QCMs in liquid These researches effectively improve our understanding in the nature of Au-S bond breakage and its breakage process. Our results show that the SLL model will improve the applications of QCM in many fields.