Objective:To explore the analgesic and anti-inflammatory effect and the immunoregulatory mechanism of polysaccharides in Radix et Caulis Acanthopanacis Senticosi. Methods①Sixty SPF Kunming mice were randomly divided into normal group, control group, positive control group and high-, medium- and low-dose groups of polysaccharides in Radix et Caulis Acanthopanacis Senticosi. Except for the normal group (10 mice), the other 50 mice were used to establish the analgesic model by the hot plate method or the acetic acid writhing method. Corresponding intervention was given to each group. Analgesicrate, writhing response inhibition rate, spleen index, thymus index and serum levels of cytokines IL-6, TNF-alpha and IL-1bet were measured in each group. ②Sixty SPF Kunming mice were randomly divided into normal group, control group, positive control group and high-, medium- and low-dose groups of polysaccharides in Radix et Caulis Acanthopanacis Senticosi. Except for the normal group (10 mice), the other 50 mice were taken to establish the model of inflammation by using egg white to induce toe swelling or using acetic acid to induce increase in peritoneal capillary permeability. Corresponding intervention was given to each group. Inhibition rate of toe swelling, inhibition rate of increase in peritoneal capillary permeability, spleen index, thymus index and serum levels of cytokines IL-6, TNF-α and IL-1β were observed in each group.  Results:①Compared with the control group, there were increase in pain threshold (P<0.05) and writhing inhibition rate (P<0.05), and decrease to varying degrees in the levels of serum cytokines IL-6, TNF-α and IL-1β (P<0.05) in the positive control group and the high-dose group, and spleen index and thymus index increased to varying degrees in the high-, medium- and low-dose groups (P<0.05). The spleen index, thymus index and the levels of serum cytokine IL-6, TNF-α and IL-1β to varying degrees in the high-, medium- and low-dose groups were higher than the positive control group (P＜0.05). ②Compared with the control group, there were increase in the inhibition rate of toe swelling and inhibition rate of increase in peritoneal capillary permeability (P<0.05), and decrease in the levels of serum cytokines IL-6, TNF-α and IL-1β (P<0.05) in the positive control group and the high-dose group, and spleen index and thymus index increased to varying degrees in the high-, medium- and low-dose groups (P<0.05). The spleen index, thymus index and the levels of serum cytokine IL-6, TNF-α and IL-1β to varying degrees in the high-, medium- and low-dose groups were higher than the positive control group (P＜0.05).  Conclusion:Polysaccharides in Radix et Caulis Acanthopanacis Senticosi improve the condition of mice in the analgesic and anti-inflammatory model. The mechanism of action may be improving the index of immune organs and regulating the levels of related immune cytokines.