Objective      To isolation and identify tendon stem cells from rat Achilles’s tendon.       Methods       Nucleated cells isolated from rat Achilles’s tendon tissues after collagenase digestion were plated at different cell densities and cultured at 37 ℃

5%CO

2

. These cells were at passage 0 (P0)

and then the cells from passages 1-3 (P1-P3) were used for the following experiments. Cell proliferation assay and colony assay were used to observe the self-renewal and proliferative potential of the obtained cells. Immunocytochemical staining and flow cytometry were employed to detect the expression of stem cell markers and lineage-specific markers. Osteogenic

chondrogenic

and adipogenic multi-differen

tiation potentials were observed by cultured in different medium.       Results      These cells were CD44h(+)

CD90(+)

CD34(-)

and CD106(-) indicated that they shared some common properties with mesenchymal stem cells. They also exhibited their unique characteristics by expressing tenogenic and stem cell markers SSEA4

nucleostemin

anti-CollagenⅠ

but not expressing CollagenⅢ. The cells also had osteogenic

chondrogenic

and adipogenic differentiation potentials by cultured in different conditions.       Conclusion      Tendon-derived stem cells with multi-differentiation potentials are successfully isolated from rat Achilles’s tendon under the optimized growth and differentiation conditions.