Worldwide, special attention is paid to the creation of high-tech silkworm breeds and hybrids of mulberry silkworms. Inbreed-breed hybrids with high technological performance of mulberry silkworm cocoon fiber have been created. Inbreed systems and new hybrids with fine silk fiber Kitayskaya 108, Ya-120, Ipakchi 1 x Ipakchi 2, Ipakchi 2 x Ipakchi 1 regionalized hybrids dry cocoon weight (0.715-0.841 g; control - 0.715-0.734 g), continuous cocoon fiber length (731-888 m; control - 744-776 m), cocoon fiber metric number (3020-3319 m/g; control - 3090-3103 m/g) proved to be significantly superior.