Abstract: Interleukin-6 (IL-6)/janus kinase (JAK)/signal transducers and activators of transcription 3 (STAT3) is a pivotal signaling pathway in the regulation of cell proliferation, survival, differentiation and T cell activation. Aberration of this pathway is involved in multiple autoimmunity diseases and cancers, therefore the pathway is considered as a hot target for drug development. In our study, we validated a cell-based model of IL-6/JAK/STAT3 and used it in screening of its inhibitors. HEK-Blue IL-6 cells of Invivogen Inc. were used to stably express IL-6 receptor and STAT3-induced secreted embryonic alkaline phosphatase (SEAP) report gene. After stimulation by IL-6, SEAP was secreted from cells and reacted with QUANTI-Blue. The product can be detected at 655 nm. The inhibitory effect of compounds on STAT3 signaling showed as IC₅₀ was calculated by OD value. The results shown that IL-6 specifically activated the cells, which could be applied to screen the inhibitors for IL-6/JAK/STAT3 signaling pathway. The optimized screening conditions were described as below:50 000 cells/well, 1 ng·mL^-1 IL-6 incubation for 20 h and reaction with QUANTI-Blue for 1 h. Based on this condition, we screened 14 natural products based on this cell model and arctigenin, cryptotanshinone and curcumin showed potential inhibitory activities on STAT3 signaling pathway with IC₅₀ of 1.28, 2.96 and 6.61 μmol·L^-1. Our study suggests that HEK-Blue IL-6 cells were suitable for screening inhibitors for the IL-6/JAK/STAT3 signaling pathway.