Background. Urate crystals-induced inflammation is a critical factor during the initiation of gouty arthritis. Berberine is well known for its anti-inflammatory activity. However, the underlying effects of berberine on monosodium urate crystals-induced inflammation remain obscure. Objectives. This study is set to explore the protective effect and mechanism of berberine on monosodium urate crystals-induced inflammation in human monocytic THP-1 cells. Methods. The mRNA levels of NLRP3 and IL-1 beta were measured by Real-Time PCR, and the protein levels of NLRP3 and IL-1 beta were determined by ELISA, Western blot, and immunofluorescence. Results. The NLRP3 and IL-1 beta expressions were significantly increased in model group compared to that in normal group (P < 0.05). Meanwhile, there was significant reduction in the expressions of NLRP3 and IL-1 beta mRNA in groups 6.25 mu M berberine and 25 mu M berberine when compared with model group (P < 0.05). Conclusions. Therefore, berberine alleviates monosodium urate crystals-induced inflammation by downregulating NLRP3 and IL-1 beta expressions. The regulatory effects of berberine may be related to the inactivation of NLRP3 inflammasome.