To explore the efficacy of modified Mahuang Fuzi Xixin Decoction on advanced tumor fever and its possible mechanism of reducing fever.Methods:A total of 119 cases of patients with advanced gastric cancer admitted in Bayannur People's Hospital during August 2014 to January 2018 were selected as research subjects.After their treatment methods were retrospectively analyzed,they were divided into control group(n = 61,underwent routine cooling treatment）and observation group(n = 58,underwent modified Mahuang Fuzi Xixin Decoction plus routine cooling treatment),with the treatment lasting for 7 d.Cooling effects of the 2 groups were evaluated and serum content of each inflammatory response index ［tumor necrosis factor alpha(TNF-α),C reactive protein(CRP),interleukin-6(IL-6)］ and distribution levels of T lymphocyte subsets(CD3+,CD4+,CD8+ T cells）in peripheral blood were measured.Results:After the 7 d treatment,therapeutic effective rate in the observation group was higher than that in the control group(P<0.05); the serum content of TNF-α,CRP and IL-6 in the observation group was lower than that in the control group; the distribution proportion of CD3+ and CD4+ T cells in peripheral blood and CD4+/CD8+ in the observation group were higher than those in the control group,while the distribution proportion of CD8+ T cells was lower than that in the control group(P<0.05).Conclusion:Modified Mahuang Fuzi Xixin Decoction can improve the cooling effects in patients with advanced tumor fever,and the specific mechanism may be related to the anti-inflammation and immunoregulation.