The aim of the studies was to assess the combinatorial qualities of the Yorkshire boar lines of import and local selection, used in the republic. The work presents the results of scientific research concerning the combinatorial performance between lines and families of Yorkshire breeds, according to reproduction indices and fattening qualities, as well as their own developmental performance (precocity, bacon thickness, body weight, viability, reproductive qualities (prolificacy, the average number of piglets at weaning, the weight of the lot and a piglet at the age of 60 days), appreciated the best variants of inter- and intrarasial combinations. As a result of the research, new data were obtained on the reproductive and productive qualities of the lines used at ÎS „Moldsuinhibrid” in various interracial and intrarasial combinations appreciated the lines with the best combinatorial results, with the following average performances in the Yorkshire breed -: the average prolificacy of the Danisua and Dansar line corresponding - 11.9 and 11.7 piglets), the weight of a piglet at the age of 2 months of the Icarus and Inel line - 20.0 kg, the lot mass of the Danidol and Icarus lines - 144 kg. The carried out studies identified the most productive combinations, with the use of imported and locally bred Yorkshire boars in intrarasial and interracial crosses with locally bred sows. The work is a completion of previous studies on imported and locally selected pig breeds, which was the basis for the creation of the selection nuclei regarding the efficiency of the improvement of the mentioned breeds, through their differentiated use in the breeding program.