The present invention discloses use of ginsenoside Rb.sub.2 in the manufacture of drugs. Said drugs not only can dissolve thrombi and protect against reperfusion injury, but also can improve microcirculation, help to repair the injured tissues and cells, improve local or even systemic physiological conditions. Additional advantages include reduced bleeding time when used in thrombolytic treatment. Said drugs may be used in a wide range of diseases related to microcirculatory disorders, such as chronic coronary heart disease, vasculitis, thromboembolic diseases, Raynaud's disease, microvascular diseases of fundus oculi and the like. According to the present invention, said drugs may be formulated into injections, tablets, granules or capsules. According to a basic embodiment of the present invention, the purity of ginsenoside monomer Rb.sub.2 may be around 80% and the rest components are essentially ginsenosides Rb.sub.1 and Rb.sub.3 in an amount of about 10%; the ginsenoside monomer Rb.sub.2 may also be in a purity of 90% or more.