We expressed spinach glycolate oxidase in yeast Sacchromyces cerevisiae. A spinach glycolate oxidase cDNA was inserted into a yeast expression vector, and the resulting recombinant DNA was expressed in yeast cells. Northern blot analysis and enzyme assay confirmed that an active glycolate oxidase was produced in the heterologous system. We characterized biochemical properties of the enzyme expressed in yeast. Basic properties, optimum temperature, optimum pH. and $K_m$, values for substrates of the enzyme appeared to be similar to those of the natural spinach enzyme. This expresssion system should be of great use to study the action mechanism of the enzyme.