Abstract: One of the biggest characteristics of breeding synthetic line was developing distinctive specialized lines to obtain the maximum and the fastest genetic progress of these specialized lines, and another was selecting those optimal specialized lines with the best combining ability for multi-line hybrids to produce commercial pigs with the maximum economic benefit. In order to support the rapid development of pig industry, Wens Group began to develop a five-way synthetic line for the demand of domestic pig market with the breeding objectives of high litter size, high feed conversion ratio and large body weight for marketing. Breeding objectives and schemes of Wens WS501 swine synthetic line was formulated to promote the development of new five-line hybrid.