Background The immunological differences between children and adults with AIDS in China are not well documented.Th1/Th2 cytokines and chemokines are two types of immune factors intimately involved in disease progression of HIV-1 infection. This study aimed to identify changes in plasma levels of Th1/Th2 cytokines inerleukin (IL)-18, IL-16, IL-10 and chemokines regulated on activation, normal T cell expressed and secreted (RANTES), stromal cell-derived factor-1 (SDF-1) and monocyte chemoattractant protein-1 (MCP-1) in HIV-1-infected children and adults in China.Methods Seventy-five children with AIDS and 35 adult AIDS patients were recruited and clinical data were collected.CD4+ T lymphocyte counts were measured by flow cytometery and plasma HIV RNA levels were measured by quantitative RT-PCR. Plasma levels of IL-18, IL-10, IL-16, RANTES, MCP-1, SDF-1α and SDF-1β were quantified by enzyme-linked immunosorbent assay. The levels of β2-microglobulin (β2-MG) and soluble Fas (sFas) were measured to validate the level of humoral and cellular immune activation.Results The mean levels of all cytokines in pediatric and adult AIDS patients were significantly higher than in their healthy controls (P <0.01). The mean levels of these cytokines were higher in pediatric patients than in adult patients (P <0.05, except for SDF-1α and β2-MG). Some of the cytokine levels in patients younger than 6 years old was higher than in older children and adults with AIDS (IL-10, IL-18, SDF-1α, MCP, RANTES and sFas, P＜0.05). Levels of IL-18, IL-10,RANTES and β2-MG of pediatric patients increased as the levels of viral load increased (P ＜0.05).Conclusions Abnormal immune activation can be measured in Chinese pediatric and adult patients with AIDS, and is higher in children than in adult patients. The cytokines levels coincide with disease progression of AIDS, but have no direct relationship with total CD4+ T cell count.