Granulocyte colony stimulating factor (G-CSF) is not only a member of hematopoietic growth factor but also a cytokine. G-CSF is known to control the production, differentiation and migration of neutrophils. LPS increasing G-CSF mRNA stability by activating p38 MAPK kinase activity, thus increases G-CSF production. There are two destabilizing elements in G-CSF 3’UTR-adenosine uridine-rich element (ARE) and stem-loop destabilizing element (SLDE) that regulate G-CSF mRNA stability. Numerous studies show that SB203580, a pyridinyl imidazole p38 MAPK inhibitors, reduces the half-life of the ARE-containing mRNA by inhibiting p38 MAPK kinase activity. However, our previous studies showed that SB203580 enhances LPS-induced G-CSF production by increasing mRNA stability. The aim of this study is to investigate the possible role of SLDE in SB203580 mediated increase in G-CSF mRNA stability in LPS treated macrophage. Our results show that G-CSF 3’UTR decreases mRNA stability in unstimulated cells, but stabilized mRNA when p38 MAPKs activity was activated by LPS. We find that the consensus sequence “TTTAATATTTA” rather than the stem-loop structure in G-CSF 3’UTR SLDE is essential for the SB230580 enhanced LPS-increased G-CSF mRNA stability. Moreover, various p38 MAPK inhibitors had different effects on the expression levels of G-CSF mRNA and protein. The levels of LPS-induced G-CSF mRNA and protein in Raw 264.7 were increased by SB203580, SB202190 and PD169316, but not by SB239063. Furthermore, we discovered that SB203580, SB202190 and PD169316 increased G-CSF mRNA stability when p38 MAPK kinase activity was inactivated. Taken together, these results suggest that SB203580 increases G-CSF mRNA stability through the highly conserved sequence and this effect is independent p38 MAPKs kinase inhibition.