Abstract: For the narrow genetic basis of maize germplasm and the lacking of excellent resistant maize inbred lines in breeding and production, the domestic inbred line‘Ye478’and exotic hybrid progeny‘P249’with tropical germplasm were used to cross, backcross and multi-generation selfing, and breed the multi-resistant and high- quality inbred line‘Zao48’with the temperate- tropical background.‘Zao48’had high multidisease resistance to stem rot, dwarf mosaic disease, corn southern leaf blight, corn northern leaf blight and ear rot. It had high content of crude protein and crude starch in grain. It also had compact plant type, dwarf stalk with lodging- resistant, strong combining ability and wide adaptability. Six hybrid cultivars including ‘Qiangsheng31’,‘Jindan44’,‘Xinyu110’,‘Yongfeng No.1’,‘Jinyang No.2’and‘Jindan70’from‘Zao48’ inbred line combination were approved by the National or Provincial Crops Variety Approval Committee. These new cultivars have been promoted and applied widely in northeastern and northern early- maturity maize regions, Huanghuaihai summer maize region, and achieved huge social and economic benefits.