Objective To investigate the trend of cytokines in patients with hemophagocytic lymphohistiocytosis (HLH) and analyze its significance.Methods 16 patients with HLH from January 2011 to May 2013 were selected.The patients were divided into remission group and death group by prognosis.Serums of the two groups were collected when they were hospitalized and at 7 th,14 th,21st,28th and 42nd day during chemotherapy,and they were fractionated HLH 1-6 groups and HLH a-d groups again,then the levels of IL-18,IL-10,IL-12,NF-κB,TNF-α and neopterin were tested by enzyme linked immuno sorbent assay (ELISA) to analysis their trend.Results The levels of all of cytokines in the remission group declined with chemotherapy,the difference between HLH1 group and another HLH groups was statistically significant (P ＜ 0.05).In the death group,the levels of NF-κB,IL-12 and neopterin had no downward trend with chemotherapy,and the difference between HLHa group and another HLH groups was not statistically significant (all P ＞ 0.05).The level of TNF-α declined with chemotherapy,and the differences between HLHa group and HLHc group,HLHa group and HLHd group were statistically significant (P =0.049,0.000).The level of IL-10 declined sharply in the first week of chemotherapy,and the difference between HLHa group and HLHb group was statistically significant (P =0.00).The level of IL-18 declined after the 2nd-weeks' chemotherapy,and the differences between HLHa group and HLHb group,HLHa group and HLHc group were statistically significant (P =0.03,0.02).Conclusions In the remission patients,the levels of serum IL-18,IL-10,IL-12,NF-κB,TNF-α and neopterin declined after chemotherapy.In the death patients,the downward trend is not obvious.It was preliminarily confirmed that the prognosis of HLH is related to the trend of cytokines during chemotherapy.