Fifty cases of the conduit valved homograft(25 cases of aortic and 25 cases of pulmonary homograft)preserved by the low temperature technique(-196℃ liquid nitrogen) were reported.The process of CVH preservation included collection,dissection, sterillization, tissue viability check-up and freezing,In 17 patients of complex congenital heart disease the right ventricular outflow tract was reconstructed with a cryopreserved CVH.Follow-up study showed encouraging early results.