To objectively verify and analyze the diagnosis and treatment rules and prescription characteristics of Professor LI Shizeng in the treatment of chronic gastritis with cross viscera therapy through data mining of clinical cases.Methods:A total of 207 prescriptions for the treatment of chronic gastritis by Professor LI Shizeng in the department from December 2017 to March 2021 were collected using the Traditional Chinese Medicine Inheritance Calculation Platform V 3.0.TheStatistical Analysis，Prescription Analysis，and Symptom Analysis functions in the Data Analysis module of the Traditional Chinese Medicine Inheritance Calculation Platform V3.0 were employed to analyze the treatment methods as well as the prescriptions and the rules.Additionally，association rules were used for network visualization of Chinese medicines.Results:Forty treatment methods were involved in all prescriptions，and the top five by frequency were spleen invigorating，stomach harmonizing，liver soothing，clearing and resolving，and heart nourishing.According to the zang-fu organs involved，there were 14 treatment methods.By analyzing the number of the prescriptions，it was found that the treatment was most carried out from the spleen and stomach，followed by the liver.There were 207 prescriptions including 146 Chinese medicines，and there were 34 medicines with the usage of frequency≥50，among which，Radix et Rhizoma Glycyrrhizae Praeparata Cum Melle，Fructus Forsythiae，Radix Pseudostellariae，Rhizoma Atractylodis Macrocephalae，Herba Taraxaci，Radix et Rhizoma Salviae Miltiorrhizae，Fructus Amomi Rotundus，Fructus Citri Sarcodactylis，Rhizoma Corydalis，and Radix Paeoniae Alba were used more than 100 times.Medicines with cold nature and those with bitter flavor were found most，and they mostly acted on the spleen.According to the efficacy，the top five prescriptions were those for tonifying，regulating qi，clearing heat，activating blood and resolving stasis，and promoting urination and draining dampness.Conclusion:Professor Li uses the cleaning method throughout the treatment of chronic gastritis，followed by using the medicines for the lung and the liver，which reflects the prescription characteristics of cross viscera therapy，and he commonly adopted medicines for invigorating the spleen，regulating qi and ascending and descending.This demonstrates his academic thought of treating chronic gastritis by cross viscera therapy.