Objective:To demonstrate the effect of cytokine with different concentration in mouse bone marrow-derived immature DCs and find the optimal cytokine dose for DC culture.Methods:mouse bone marrow-derived immature DCs were cultured in the presence of low

moderate and high dose of GM-CSF cytokine with or without IL-4.The morphology of cells were observed and the phenotype were detected.Results:On day 7

DCs in low dose group had the least quantity

small cell process and low expression of CD80

CD86 and MHC class II.The quantity of DCs increased if cultured with IL-4;DCs in moderate dose group and high dose group were more than that in low dose group and the expression of CD80

CD86 and MHC classⅡwere higher

but it is no difference between moderate dose group and high dose group

however cultured with or without IL-4.Conclusion:Higher purity of immature DCs could be get when cultured with low dose of GM-CSF.It was no difference of yield and purity of immature DCs when cultured with moderate or high dose of GM-CSF whether or not combine IL-4.