Abstract: The present invention relates to a pharmaceutical composition for treating cardiovascular and cerebrovascular diseases and the method of preparation thereof. The aforesaid pharmaceutical composition is prepared by the following components in weight percent: 0.1%-0.3% scutellarin, 20%-25% co-surfactant, 40-50% surfactant, and 25-30% oil. The method of preparing the aforesaid pharmaceutical composition comprises the steps of: (1) dispersing scutellarin in co-surfactant and surfactant to obtain a mixture; (2) dispersing the mixture from step (1) in oil, and thermostatically and magnetically stirring the dispersion mixture under the temperature of 25° C. to 37° C., such that the components thereof are completely dissolved to obtain the pharmaceutical composition. Through the use of the selected pharmaceutical adjuvants having the ability to inhibit MRP2, the aforesaid pharmaceutical composition effectively improves absorption and bioavailability of scutellarin.