Objective To analyze Professor LIU Hong-xu’s TCM medication characteristics and prescription rules for patients after percutaneous coronary intervention（PCI）based on data mining.Methods Collect prescriptions for patient after PCI prescribed by Professor LIU Hong-xu from January 1,2013 to December 31,2018 in the Beijing Hospital of TCM,and establishing a database of TCM formulas.Frequency statistics,association rules analysis,system cluster analysis were conducted.Results There were totally 489 formulas included involving 162 kinds of herbal medicines and 47 kinds with the appearance frequency no less than 10%.There were 135 correlations obtained from association rules analysis and 13 combinations obtained from clustering analysis.Conclusion Professor LIU Hong-xu treats patients after PCI by combining several prescriptions according to monarch drug,minister drug,assistant drug and servant drug; at the same time,he is good at using paired drugs and takes tonifying qi and yin as the major treatment principle,and eliminating stasis and resolving phlegm as the basic principle,accompanied by invigorating the spleen and draining the lung,soothing the liver and tranquilizing the mind.