Objective:To determine the effects of FL,rIL 6,rIL 6R in vitro expansion and differentiation of human cord blood CD34 + cells.Methods:Human cord blood CD34 + cells were enriched by magnetic cell isolation system CD34 + cells were incubated in the presence of FL,rIL 6,rIL 6R and their various companision.The total number of cells and colonies were counted at various time intervals.Results:The expanded cells by FL,rIL 6,rIL 6R showed colonies were CFU GM mainly but rIL 6+rIL 6R and FL+rIL 6+rIL 6R,showed some BFU E and CFU Mix but no CFU MK.Erythrocyte cells were conformed and total cells were increased 6.4 folds by FL+rIL 6+rIL 6R.Conclusion:Human cord blood CD34 + cells could expanded and differentiated by FL+rIL 6+rIL 6R.