Glycosaminoglycans (GAGs) were isolated from the porcine testis, and their immunomodulating and anticoagulant activity was investigated. From anion exchange chromatography (Dowex Macropolous Resin) used for further isolation of porcine testis GAGs (PT-GAGs), two fractions (PT-GAG-1.5 and PT-GAG-16) eluted by different salt concentration were obtained. In immunomodulating activity test, PT-GAG-1.5, but not PT-GAG-16, significantly enhanced the growth of murine peritoneal macrophages. In addition, treatment with PT-GAG-1.5 induced the production of cytokines, interleukin-1beta (IL-1beta), interferon-gamma (IFN-gamma) and tumor necrosis factor-alpha (TNF-alpha), from murine microphages. Unexpectedly, both of PT-GAGs had no effect on the growth of murine splenocytes. The anticoagulant activity of PT-GAG-1.5 and PT-GAG-16 was examined by activated partial thromboplastin time (aPTT) assay and thrombin time (TT) assay. Both of PT-kGAGs significantly increased the clotting times of aPTT and TT in a dose-dependent manner. The anticoagulant activity of PT-GAG-16 was found to be higher than that of PT-GAG-1.5. These results suggest that PT-GAGs possess biological activities such as immunomodulating activity and anticoagulant activity.