Abstract:[Objective] To explore the effects of intraarticular injection of anodonta glucan (HBP-A) in different dosages on cartilage de- generation of the knee, and related markers in guinea pigs. [Methods] Twenty guinea pigs were randomly divided into five groups, including the normal group, model group, low concentration group, medium concentration group and high concentration group, with 4 animals in each group. Four animals in the normal group were treated with right knee sham operation, while the remaining all animals were treated with ante- rior cruciate ligament transection of right knee to establish osteoarthritis (OA) model. Three days later, the normal group and model group were injected with normal saline into right knee joint, while the low, medium and high dose groups were injected with 7.5 mg/ml, 15 mg/ml and 30 mg/ml of HBP-A 200 μl, respectively, once a week for consecutive 5 weeks. Five weeks later, the animals were sacrificed, and the right knee samples were harvested for histological, immunohistochemical and qPCR assays. [Results] With histological observation, signifi- cant changes of cartilage degeneration were found in the model group compared with those in the normal group, whereas which significantly reversed in a dosage-dependent manner in the 3 groups with HBP-A in different dose. OARSI score in the model group was significantly higher than that of the normal group (P<0.05) , which significantly decreased in a dose-dependent manner in the 3 HBP-A groups (P<0.05) . In terms of immunohistochemistry, the optical density (OD) values of ALP, Ihh, Runx2 and MMP13 in the model group were significantly higher than those of the normal group (P<0.05) , whereas which declined significantly in the 3 HBP groups in the dose-dependent manner (P<0.05) . As results of qPCR assay, the mRNA relative expression levels of IL-1β, Ihh, Runx2 and MMP-13 in the model group were signif-icantly higher than those in the normal group (P<0.05) , which also reduced significantly after injection of low, medium and high concentra- tions of HBP-A into the joint cavity in the dose-dependent manner (P<0.05) . [Conclusion] In this study, intraarticular injection of HBP-A does reduce or delay the cartilage degeneration of the knee in guinea pigs.