Abstract： Objective To approach the immunomodulatory effects of hypertonic saline (HTS) on sepsis patients.Methods Twenty-four septic patients admitted to surgical intensive care unit (SICU) received 5％ HTS for fluid resuscitation were prospectively enrolled from January 2009 to September 2010.Blood samples were collected at 15 minutes before,and at 15 minutes and 6,12,and 24 hours after HTS infusion,the ability of respiratory burst of polymorphonuclear neutrophils (PMN) and the surface expression of CD11b and L-selectin in fresh whole blood was evaluated with flow cytometer.The plasma was collected to determine the solubility intercellular adhesion molecule-1 ( sICAM-1 ),solubility L-selectin ( sL-selectin ),tumor necrosis factor-α ( TNF-αt ) and interleukins ( IL-6,IL- 1β ).Results The baseline before HTS infusion was set as 100.Six hours after HTS infusion,the ability of respiratory burst of PMN was significantly increased [ ( 160.0 ± 19.6)％ ] compared with the baseline (P＜0.05),and then gradually recovered to normal level.The expression of CD11b and L-selectin in the surface of PMN was reduced rapidly at 15 minutes after HTS infusion,and to nadir at 12 hours [ ( 70.4 ± 5.7 )％,( 70.6 ± 8.1 )％ ],and L-selectin recovered to the normal level at 24 hours.Within short-term of HTS infusion,plasma inflammatory factor TNF-α was significantly decreased,and sustained a low level until 12 hours,and then gradually increased.There was no change in IL-1β.IL-6 and sICAM-1 was gradually increased,and peaked at 24 hours and 12 hours respectively,and remained at a high level.sL-selectin increased shortly at 15 minutes after HTS infusion compared with baseline,and remained the level to 12 hours,and recovered to baseline at 24 hours.Conclusion Delayed administration of HTS may have an immunomodulatory effect on sepsis patients,which could inhibit the activation of PMN.