Objective： To compare the histological, immunological, and biomechanical characteristics of decellularized porcine aortic valve scaffold created by 3 different decellularization protocols and to search for a more suitable technique for creating aeellular tissue-engineered cardiac valve conduit. Methods： Porcine aortic valve leaflets and whole aortic roots were deeellularized by 3 different protocols. Decellularization procedure in group Ⅰ involved treatment with 0.01% trypsin, 1% Triton, and nuclease for 24 h; that in group Ⅱ involved treatment with 0.01% trypsin （8 h）, 1% DCA, and nuclease for 24 h; and that in group Ⅲ involved treatment with 1% DCA and nuclease for 32 h. All the treatments were conducted during continuous shaking at 37℃. Porcine aortic valve leaflets and whole aortic roots treated with PBS were taken as control. The deeellularization efficiencies of each protocol were assessed by H-E staining, scanning electron microscopy, and transmission electron microscopy. The biomechanical features of the acellular valve matrices were examined by stress-strain tests and tensile strength tests. The immunogenicity and inflarfimatory responses of the decellularized matrices, valve leaflets, and aortic wall were investigated by subcutaneous implantation of them in rats. Results： The native ceils in porcine aortic valve leaflets and aortic roots were completely removed in group Ⅱ , which was superior to group Ⅰ and Ⅲ. The values of elasticity modulus and ultimate tensile strength （UTS） of groupⅡ were greater than those in group Ⅰ （[5.77±0. 951 MPa vs [4.15±1.13] MPa and [7.82± 1.51] MPa vs [4.65±0.85] MPa, respectively; P〈0.05）. The extension ratios at 1.5 MPa and at rupture in group Ⅱ were less than those in group Ⅰ （[0.33±0.04] vs [-0.41±0. 091 and [-0.45±0. 021 vs [-0.60±0. 06]; P〈0.05）, but the extension ratio at rupture was similar to that of fresh porcine aortic valves （ [0.45±0.02] vs （[-0.46±0.03]）. Histological analysis showed only slight inflammatory responses in grouplland the host cells grew into the matrix, rebuilding the acellular matrices gradually. Conclusion： Decellularization using 8-hour pretreatment with 0. 01% trypsin, followed by 24 hours incubation with 1% DCA plus nuclease is effective and convenient; it not only removes the cells but also decreases the immunogenicity of the aortic valve matrices, making the product an excellent material for tissue-engineered cardiac valve conduit.