Pericellular matrix (PCM) is a narrow tissue region surrounding chondrocytes, which "chondron" with its enclosed cells. A number of studies suggested that PCM is rich in proteoglycans, collagen and fibronectin, and plays an important role in regulating microenvironment of chondrocytes. Direct measures of PCM properties through micropipette aspiration technique showed that PCM was different from mechanical property of chondrocytes and nature extracellular matrix. However, the function of PCM is not clear, and need further study.