Abstract: OBJECTIVE To investigate the correlation between physical parameters and chemical components of prepared slices and pills of different processed products of Paeoniae Radix Rubra. METHODS Pills of different processed products of Paeoniae Radix Rubra were prepared by general method. Physical parameters(relative density, pH value and oxidation value) of different processed products and pills were determined. The content of paeoniflorin and starch was determined by HPLC and UV, respectively. In vitro dissolution of pills was fitted used Weibull equation. SPSS20.0 combined with Matlab and Graphad prims 6.0 was used to analyze the correlation between physical parameters and chemical components, and the regression model was established. RESULTS The physical parameters, pH value, the content of paeoniflorin and starch had significant correlation between different processed products of Paeoniae Radix Rubra and their pills. According to the correlation fitting regression model, all of them were related to the pH value. The fitting degree was good, and the R² was >0.9. Therefore, the pH value could be selected as index for the quality control of the different processed products of Paeoniae Radix Rubra and their pills. The results of dissolution experiment showed that the processed products prepared by wine, vinegar or salt had certain promoting effect on the dissolution of pills. CONCLUSION The study selects physical parameters, macromolecules(starch), and small molecules(paeoniflorin) to conduct a comprehensive investigation, revealing the changing laws of physical parameters and chemical components. The regression model between physical parameters(pH value) and chemical components explaines the dynamic change process from processed products to pills, analyze and predict the quality of pills prepared from different processed products of Paeoniae Radix Rubra, and provide reference for the quality control of their pills.