Objective To investigate the effects of interleukin-1β (IL-1β) and tumour necrosis factor-α (TNF-α) on the degradation of extracellular matrix of articular chondrocytes, and explore the related molecular mechanism. Methods Primary articular chondrocytes were isolated from rat articular chondrocytes, and were stimulated by IL-1β and TNF-α alone or in combination. IL-1β stimulation group, TNF-α stimulation group and IL-1β and TNF-α stimulation group were established, and control group without any stimulation was also established. After treatment for 24 h, 48 h and 72 h, the changes of extracellular matrix of articular chondrocytes were observed by inverted microscope, and Real-time PCR was employed to detect the expression of metalloproteinase-13 (MMP-13), Aggrecanases-1 (Adamts-4) and Aggrecanases-2 (Adamts-5) mRNA. Results After treatment for 48 h and 72 h, it was observed by microscope that there was no significant difference in degradation of extracellular matrix of articular chondrocytes between control group and TNF-α stimulation group, while extracellular matrix of articular chondrocytes in IL-1β stimulation group and IL-1β and TNF-α stimulation group was unstained and degraded with expanded cell spaces. Compared with control group, the expression of MMP-13, Adamts-4 and Adamts-5 mRNA in IL-1β stimulation group significantly increased after treatment for 24 h （P<0.01）, and decreased after treatment for 48 h and 72 h. There was no significant difference in the expression of MMP-13, Adamts-4 and Adamts-5 mRNA between IL-1β stimulation group and IL-1β and TNF-α stimulation group after treatment for 24 h, 48 h and 72 h （P>0.05）. Conclusion IL-1β can directly degrade extracellular matrix of articular chondrocytes through up-regulation of expression of MMP-13, Adamts-4 and Adamts-5, while TNF-α can not directly degrade extracellular matrix of articular chondrocytes.