Abstract ： Objective ： To explore the mechanism of the damp-heat external environment in the inflammatory response of Lingnan damp- heat syndrome and the intervention mechanism of Artemisiae Scopariae Herba. Methods：In experiment 1，48 SPF grade male BALB/c mice were randomly divided into four groups： the control group [T (25±2) ℃ ， HR 55%]， the Lingnan damp-heat external environment model group [T (33±2) ℃，HR 85%]，the high fever group [T (33±2) ℃，HR 55%]，and the dampness obstruction group [T (25±2) ℃ ， HR 85%]. After 12 hours of exposure， the model was established for 28 days. The food intake of the mice was recorded daily， and the body mass of the mice was recorded weekly. On the day 14 and 28 of modeling， enzyme- linked immunosorbent assay (ELISA) was used to detect serum levels of inflammatory factors such as interleukin- 6 (IL- 6)， IL- 18， and IL- 1β， tumor necrosis factor-α (TNF-α)，nuclear transcription factor κB (NF-κB) and Toll-like receptor 4 (TLR4) in each group of mice. In experiment 2，50 SPF grade male BALB/c mice were randomly divided into three groups： normal group：Lingnan damp-heat external environment model group，low-，medium-，and high-dose groups of Artemisiae Scopariae Herba. The model group and three groups of Artemisiae Scopariae Herba were placed in an artificial climate box [T (33±2) ℃，HR 85%]，and exposed for 12 hours to create a dampheat external environment. After 14 days of modeling， three groups of mice with Artemisiae Scopariae Herba were given intragastric administration of three different concentrations of Artemisiae Scopariae Herba decoction for 7 consecutive days. The detection method and indicators are the same as above. Results：In experiment 1， after 14 days， 14- 28 days and 28 days of modeling， compared with the control group， high fever group， and dampness obstruction group， the serum TNF- α of the model group mice was increased (P＜0.05，P＜0.01). There was no statistically significant difference in the comparison of IL- 18， IL-6，NF-κB and TLR4 in each group (P＞0.05). At days 14-28，IL-1 β in high fever group compared with the Lingnan clamp-heat external environment model group，the difference was statistically significant (P＜ 0.01). Experiment 2，compared with the model group，the serum TNF-α levels in the low-，medium-， and high- dose groups of Artemisiae Scopariae Herba were decreased (P＜0.05，P＜0.01). There was no statistically significant difference in comparison of IL- 18，IL- 1β，IL- 6，NF- κB and TLR4 in each group (P＞0.05). Conclusion：The damp-heat external environment up-regulates serum TNF- α levels to trigger the inflammatory response of Lingnan damp heat syndrome is caused by the joint action of "pathogenic factors of external dampness" and "pathogenic factors of external heat"， and Artemisiae Scopariae Herba can improve this pathological process through this mechanism.