The present invention provides a composition comprising an effective amount ofan extract product of a Dioscorea species named as Dioscorea alata (No. YMM-PH3)capable of promoting proliferation and differentiation of bone marrow cells inthe subject,wherein the Dioscorea alata (No. YMM-PH3) is characterized by a randomlyamplifiedpolymorphic DNA (RAPD) fingerprint including 14 DNA bands ranging from 428bp,452bp, 537bp, 602bp, 723bp, 817bp, 934bp, 1140bp, 1242bp, 1478bp, 1641bp,1904bp,2151bp and 2918bp, respectively, when genomic DNA of the Dioscorea alata (No.YMM-PH3) is amplified with a primer of SEQ ID NO: 9, and the extract productisprepared by a process including the steps of: (a) extracting a tuber of theDioscorea alata(No. YMM-PH3) using an alcohol-based solvent in the presence of acetic acid；(b)subjecting the resultant product obtained in step (a) to a separatingtreatment to obtain asoluble fraction； and (c) removing solvent from the soluble fraction obtainedin step (b)extract fractions of the Dioscorea alata (No. YMM-PH3).
