To explore the composition rules of qi tonic of Chinese patent medicine. Methods: The formula of qi tonic of Chinese patent medicine in The New National Medicine were collected to achieve the frequency of herbs and association rules between herbs by the methods of association rules with apriori algorithm and complex system clustering algorithm. Results: The most frequently used herbs were Milkvetch Root, Chinese Angelica, Prepared Rehmannia Root, Indian Bread, White Atractylodes Rhizome etc. The most frequently used herb combinations were Chinese Angelica and Milkvetch Root, Prepared Rehmannia Root and Milkvetch Root, as well as Debark Peony Root and Prepared Rehmannia Root etc. The herbs with a high confidence degree of association rules include “Sichuan Lovage Rhizome, Prepared Rehmannia Root>Chinese Angelica”, “Debark Peony Root, Prepared Rehmannia Root>Chinese Angelica” etc. Conclusion: Besides qitonifying herbs, the Chinese patent medicine prescriptions of the type also include some tonics with yin nourishing, fluid production and blood tonifying herbs etc.