A pharmaceutical composition for treating diabetes, and its process for preparation.The pharmaceutical composition comprises the extracts of following Chinesemedicinal materials in weight portions: Rhizoma Pinelliae 1-12, Fructus AurantiiImmaturus 3-15, Fructus Mume 5-20, Rhizoma Coptidis 1-12, Radix Paeoniae Alba3-15, Radix Et Rhizoma Rhei 1-6, Radix Scutellariae 3-15, Radix Trichosanthis5-40, Radix Bupleuri 10-30, and optionally excipients pharmaceutically acceptable.Fructus Crataegi could be comprised as a material in the composition. The pharmaceuticalcomposition of the present invention can be preparated by four kinds of processes..