Objective.To determine whether malariotherapy (an old therapy for treatment of neurosyphilis)improves some clinical and laboratory parameters of HIV-positive patients without iatrogenic complications.Methods.Total 8 asymptomatic HIV-1 positive subjects whose CD4 cell counts were over 250×106 cells/L were selected for the phase-1 studies of malariotherapy and were intravenously injected Plasmodia vivax to induce artificial malaria.Malaria was terminated with chloroquine after 10～20 malarial fever episodes.Cell-bound CD4 levels were measured by APAAP (a solid-phase enzyme essay)and levels of neopterin (NPT),beta-2-microglobulin (B2M),soluble tumor necrosis factor receptor-2(sTNF-RII),interleukin-2(IL-2)and HIV P24 antigen were measured by ELISA. Patients were followed up to 24～30 months.Results.CD4 levels increased in 5,NPT decreased in 7 of 8 patients;IL-2 increased in 5 of 6 patients after malariotherapy.The total trends of B2M and sTNF-RII basically remained stable.HIV P24 antigen remained undetectable in 6, remained detectably low level in 1 and experienced increase in 1 of 8 patients after malariotherapy.No any severe complications occurred in all 8 patients.Conclusions.The results indicate that malariotherapy basically is safe for HIV infection and it seems that the therapy improves some immunological parameters of HIV patients.