Abstract: The invention provides the use of ursolic acid saponin and oleanolic acid saponin of formula (I) in preparing medicaments for increasing leucocytes and/or platelets. The invention also provides a pharmaceutical composition containing the same compound. The invention utilizes the cheap and accessible ursolic acid and oleanolic acid which are widely present in natural plants as raw materials, introduces monosaccharyls or oligosaccharyls by structural modification. It is proved by pharmacological tests that the compound of formula (I) have an activity of obviously increasing leucocytes and/or platelets.