Abstract: OBJECTIVE To study the effect of Astragaloside IV on the IL-1β expression of degenerative joint cartilage in human knee osteoarthritis(OA). METHODS Degenerative joint cartilage cells of postoperative knee OA patients were isolated， cultured and passaged in vitro. The third generation cells were identified by HE and type Ⅱ collagen immunofluorescence staining， and then were stained by IL-1β immunofluorescence. They were divided into 6 groups after the cell degenerative situation was observed (Group A: cartilage cells + DMEM control group; Group B: cartilage cells + 25 mmol/L Astragaloside IV; Group C: cartilage cells + 50 mmol/L Astragaloside IV; Group D: cartilage cells + 75 mmol/L Astragaloside IV; Group E: cartilage cells + 100 mmol/L Astragaloside IV; Group F: cartilage cells + 500mmol/L Astragaloside IV)， and real-time fluorescent quantitative PCR was used to detect IL-1β expressing mRNA in degenerative cartilage cells of every group in 4 h， 8 h， 24 h， 48 h and 72 h. RESULTS ①Morphologic observation. Spindle cells and polygonal cells were found in the initial generation cells at the same time. Nucleus located at the side of the cell， closing to the membranes， and the cell filaments were long. HE stained the cytoplasm into red and the membranes into blue. Toluidine blue stained the cytoplasm and membranes into dark blue. The positive type Ⅱ collagen stain was green fluorescence. The nucleus were restained by 4'，6-diamidino-2-phenylindole. Activated by fluorescence in various wave bands， the plasm and membranes presented clear green fluorescence， while the nucleus areas showed no obvious green fluorescence， which proved that type Ⅱ collagen mainly distribute in plasm and membranes， and the cultured cells were cartilage cells indeed. The clear green fluorescence could be seen after IL-1 immunofluorescence staining， and polygonal cells were dominated among cartilage cells. ②IL-1 mRNA expression. The IL-1 mRNA expression levels in different time showed difference (F=13.236，P<0.01); and those in different groups were different as well， Group A higher than Group B， C， D， E (P<0.05~0.01) and Group F higher than Group A， B， C， D， E (P<0.05~0.01); the factors of time and group had interaction effect (F=7.262，P<0.01). CONCLUSION Astragaloside IV with a certain concentration can delay the degeneration of cartilage cells by inhibiting IL-1 synthesis in the degenerative cartilage cells， but it with a excessive high concentration will speed up the degeneration by promoting IL-1 synthesis.