Objective  To investigate β1 integrin expression during development and growth cycle in hair follicle of SD rat dorsal skin.   Methods  β1 integrin expression was detected by immunohistochemistry at E175

E18.5

E19

E20 and postnatal day 1

7

29.    Results  β1 integrin expression was negative in hair follicle of E17.5

E18.5

E19

E20

positive in epidermis of E17.5

E18.5 and turned to be negative in E19

E20. β1 integrin expressed in outer root-sheath of hair follicle at postnatal day 1

7.   Conclusion  β1 integrin can be a good hair follicle stem cell marker in anagen and is very important for hair follicle stem cell to maintain its stability.