Objective: To compare carotid catheters blooddrawing and tail-cut blooddrawing in traumatizing rats and changing their internal L-selectin. Methods: Two ways of bloodletting were selected to produce hemorrhagic shock models. Monoclonal antibody sign and flow cytometer were used to test neutrophil L-selectin dynamic expression in rats. Results: No remarkable differences were shown among different time points in neutrophil L-selectin expressing amount (average fluorescence index)( P ＞ 0.05). Compared with the normal control group, all cell surface expressions in empirical control group increased. Cell surface expressions reached the summit at 3 hours and kept the high level at 4-5 hours. A progressive increase of the mRNA expression peaked at 5 hours; the expressions in both groups of carotid catheters blooddrawing increased compared with normal control group, and remained stable after 3 hours compared with the Tail-cut Blooddrawing Group. Conclusion: L-selectin expressions changed little in tail-cut blooddrawing rats, while carotid catheters resulted moderate or sever trauma. Therefore, it was suggested that it should not be set as hemorrhagic shock control model. As neutrophil L-selection expressions increased after trauma, the adhesion of leucocytes to the venule wall may be beneficial to the healing of wound and enhance the ability of anti-infection. The immediate increasing of neutrophil surface L-selectin expressions in this study was likely due to the direct release of Lselectin from cytoplasm granules that do not depend on protein synthesis.