The unique characteristics of cell surface molecules on human bone marrow stromal cells (hBMSCs) have not been clearly elucidated. The authors characterized 19 cell surface molecules on culture-expanded hBMSCs obtained from 10 human donors, by flow cytometry, calculated the averages and standard deviations of the expression frequencies of individual surface molecules, and evaluated their expression patterns with respect to donor-dependent variations. Surface molecules expressed at frequencies of more than 80% on cells included, CD49e, CD29, CD90, CD73, CD44, CD105, and CD146, those expressed at frequencies of 20-80% included, Stro-1, CD51, CD54, CD31, CD106, CD163, and CD34, whereas CD49d, CD14, CD144, CD11b, and CD45 were expressed at less than 20%. Substantial donor-dependent variations (>10% standard deviation in expression percentage) were observed in the expressions of CD105, Stro-1, CD51, CD54, CD31, CD106, CD163, and CD34. Our results demonstrate that CD49e, CD29, CD90, CD73, and CD44 can be used as a positive marker for hBMSCs, and that CD144, CD11b, and CD45 could be used as a highly selective negative marker. However, the expressions of CD54, CD31, and CD106 observed in the present study, contradicted prior reports and thus, their expressions remain controversial.