The paper describes creation and analysis of a database 3Dfold_test. This database consists of a large set of pairs of spatially-similar structures of protein domains and of an accompanying, much larger control set of "decoys", i.e., spatially-dissimilar protein structures, having approximately the same size and compactness as each member of a pair of spatially-similar proteins. The database 3Dfold_test can be found at the site http://phys.protres.ru/resources/prediction analogy/3Dfold/.