Objectives : Since its enactment in 1987, the 56 standard prescriptions covered by insurance have remained unchanged from its original version. In this study, we tried to discover most frequently used herbal combinations by analyzing prescriptions used in actual clinical settings. Methods : We have built Structured Query Language to analyze herbal combination and progressed this analysis through analyzing the frequencies of medicinal herb combinations in medical prescription slips. Results : We have found out that traditional Korean medical doctors use about 13 herbs in a prescriptions and usually use 253 kinds of herb. And We have found out the most frequently used herbal combination. Conclusions : In this study, We can suggest new method to decide what do we need on insurance prescriptions.