Objective:To analyze the composing principles of the prescriptions for seminal emission collected in 〈The Dictionary of Prescriptions in Traditional Chinese Medicine〉 using TCM inheritance system.Method: The prescriptions treating seminal emission in the 〈Dictionary of Prescriptions in Traditional Chinese Medicine〉 were collected and the composing principles were analized by using revised mutual information

complex system entropy clustering and so on based on the TCM inheritance system.Result: Three hundred and seventy prescriptions involving 282 herbs were studied.The herbs for invigoration or astringent were used in the highest frequency

of which

Poria appeared 129 times

being 34.9% in total prescriptions.Rhizoma Dioscoreae and Poria as a pair of herbs appeared 66 times

Rhizoma Dioscoreae

Fructus Schisandrae Chinensis and Radix Rehmanniae Praeparata as a 3 item set appeared 35 times

Fructus Corni

Rhizoma Dioscoreae

Pradix Rehmanniae Praeparata and Poria as a 4 item set appeared 22 times

being the highest in frequency.The analysis on association rule showed that Rhizoma Anemarrhenae was coupled with Cortex Phellodendri Chinensis

Stamen Nelumbinis with Semen Euryales

Fructus Corni and Poria with Rhizoma Dioscoreae

Radix Morindae Officinalis and Poria with Herba Cistanches.Thirty six core combinations and seven new prescriptions are mined from the database.Conclusion: The prescriptions for treating seminal emission are mainly composed with herbs for invigoration

assisted by tranquilizing and/or astringent herbs.This pattern will provide a reference for clinical practice.