Objective To establish synovial cell primary cultures and a lipopolysaccharide ( LPS)-induced fibroblast-like synoviocyte ( FLS) inflammatory model of a normal knee joint in Sprague-Dawley ( SD) rats. Methods Normal knee joint synovium (80-120 g) was separated from specific-pathogen-free SD rats in an ice bath with phosphate- buffered saline. The primary synovium was cultured to the 3rd generation. Vimentin expression and FLS proliferation were detected via immunohistochemical staining and the 5-ethynyl-2′-deoxyuridine method. Synovial tissue was used as a control to detect characteristic protein expressions in the FLS in the 3rd-8th generations of primary culturing and to screen the FLS for high purity and physiological functions for use in subsequent experiments. After LPS-induced FLS inflammation, the mRNA and protein expressions of IL-1β and TNF-α were detected at different time points to determine the time point at which LPS could successfully induce an FLS inflammatory model. Finally, the cytokine expression, proliferative functions and characteristic proteins of the FLS before and after LPS induction were detected to provide experimental data to evaluate the FLS inflammatory model. Results FLS primary cells were successfully cultured with 0. 2% collagenase I digestion. The FLS purity in the 3rd generation exceeded 98% for detecting vimentin. By detecting characteristic FLS proteins, FLS with physiological functions that could be used for subsequent experiments were selected as the primary cells from the 3rd-7th generations. Analyzing the cytokines and characteristic proteins in FLS before and after LPS induction revealed that 1 μg / mL LPS is required to stimulate FLS cells for 3 h to replicate the FLS inflammatory model. Conclusion The LPS- induced FLS inflammatory model can be used to study inflammatory arthritis in vitro.