‘Mudou8’, bred by Mudanjiang Branch of Heilongjiang Academy of Agricultural Sciences, is a high oil and high yield soybean cultivar, is welcome by soybean planters with high yield, drought resistance and high quality. Based on ancestors tracking and pedigree tree building, we analyze ‘Mudou8’ parent geographical origin and nuclear genetic contribution, and reveal its genetic basis, this research can provide a reference for soybean breeding parent selection and use. ‘Mudou8’ belongs to Sihuang cytoplasm family, transfer process is: ‘Silihuang’ → ‘Mancangjin’ → ‘Ke5501-3’ → ‘Suinong3’ → ‘Suinong4’→ ‘Suinong8’ → ‘Kennong19’ → ‘Mudou8’. Nuclear genes are provided by the ancestors, including ‘Nongda4840’, ‘Hkeshangsilijia’, ‘Xiaolidou9’, ‘Tokchi’, ‘Nagaha’, ‘Amsoy’, ‘Silihuang’, ‘Jinyuan’, ‘baimei’, ‘Yongfengdou’, ‘Xiaolihuang’, ‘Huang-zhong-zhong20’ and ‘Jiamusitujiazi’. Nuclear genetic contribution rate respectively is:25%, 15.23%, 12.5%, 12.5%, 7.81%, 7.28%, 7.28%, 5.96%, 3.13%, 2.34%, 0.78% and0.20%.