Objective:To explore the effects of meningeal lymphatic vessel transport dysfunction on lipopolysaccharide(LPS)-induced central nervous system inflammation in mice. Methods:Firstly,sixteen C57BL/6 mice were randomly divided into four groups, normal saline was injected intraperitoneally in the Control group. The LPS groups were injected intraperitoneally with LPS(2 mg/kg), and then the transport function of meningeal lymphatic vessels,activation of microglia and levels of interleukin-6(IL-6)and interleukin-1β (IL -1β)in the hippocampus were observed after 12 h,24 h and 72 h. Secondly,eight mice were randomly assigned to two groups: Control group and VEGFR3 inhibitor MAZ51 group,to observe the effects of MAZ51 on the transport function of meningeal lymphatic vessels. Finally,twenty-four mice were divided into four groups as follows:control group,MAZ51 group,LPS group,and LPS+MAZ51 group. MAZ51(10 mg/kg)was preinjected intraperitoneally into MAZ51 group and LPS+MAZ51 group for five days per week with a total of 30 days. After six weeks,LPS was injected into LPS group and LPS+MAZ51 group. A day later,behavioral experiments that assess the ability of mice to escape from fear were conducted;the activation of microglia in the hippocampus was measured by immunohistochemistry;the expression of IL-6 and IL-1β was evaluated by ELISA method. Results:The area of LYVE-1 in meninges and the area of OVA-647 in the deep cervical lymph nodes were significantly decreased 24 h after intraperitoneal injection of LPS(P < 0.01),and were lower than the basal level for 72 h(P < 0.01). The activation of microglia and levels of IL-6 and IL-1β in the hippocampus were significantly increased after 24 h(P < 0.01). Compared with the control group,the area of OVA-647 fluorescence in the MAZ51 group was significantly reduced(P < 0.01). The activation of microglia and the expression of inflammatory factors in the hippocampus of mice in the LPS+MAZ51 group were increased(P < 0.01)and the freezing time was significantly reduced(P < 0.01). Conclusion:The impairing transport function of meningeal lymphatic vessels aggravates LPS-induced central inflammation and cognitive dysfunction in mice by increasing inflammatory mediator accumulation and activating microglia.