Change of skin bacteria population would show diverse outcomes both improve or worse in skin condition. Human skin is a habitat that support a wide range of microorganisms. Skin also serve a physical barrier to protect whole body from external factor as foreign organisms or toxic substances. Not only skin itself help to protect our bodies to be health but symbiotic skin bacteria is involved to maintain or improve skin condition and protect body from potential infection. The strain specific growth change of skin bacteria was evaluated with the Coix lacryma-jobi L. seed extract to support growth change of commensal skin bacteria using colony forming unit method. The Coix lacryma-jobi L. seed extract did not change the cell growth of Streptococcus aureus significantly under the tested condition. However, it increased the cell growth of S. epidermidis, skin commensal bacteria, by up to 50% of relative cell density comparing to control. The overall result suggested that a strain specific cell growth enhancement will result in the improvement of bacterial flora on the skin by the Coix lacryma-jobi L. seed extract treatment. The Coix lacryma-jobi L. seed extract would be a good materials to improve skin commensal bacteria which help to control overall number of pathogenic bacteria to avoid any chance of skin disease.