Periosteum-derived progenitor cells (PDPCs) were isolated by characteristic surface markers. Reproducibility of immunophenotypes of the PDPCs was characterized by flow cytometric analysis using fluorescence-activated cell sorter (FACS). SH2(+), SH3(+), SH4(+), CD9(+), CD90(+) and CD105(+) were important eternal characteristic cell surface markers for the PDPCs. The characterized PDPCs maintained their chondrogenic potential in pellet cultures until the 15th passage from primary cell culture.