Wancao No.2 is the first hybrid variety of sorghum and Sudan grass in China. It’s characteristic of high yield， good quality and strong adaptability. In the study， genetic analysis was conducted on the five agronomic traits of plant height （PH）， stem diameter （SD）， tiller number （TN）， fresh weight per plant （FW） and dry weight （DW） of Wancao No. 2 in the recombinant inbred line （RIL） population. SSR molecular markers were used to construct the genetic map of RIL population of Wancao No.2. QTL mapping was carried out for five agronomic traits including PH， SD， TN， FW and DW. The analysis of these five agronomic traits showed that the average value PH， SD， TN， FW and DW of RIL population were between their two parents， and the other four agronomic traits showed normal distribution except TN. The genetic map of 10 linkage groups was constructed using 147 SSR markers. The total genetic distance was 1，030.4 cM. The average distance between markers was 7.14 cM. A total of 22 QTLs controlling the five agronomic traits were further mapped by genetic map， including 1for PH， 2 for SD， 6 for TN， 7 for FW and 6 for DW. Among these 22 QTLs， qFW-6 had the smallest phenotypic variation explanation of 3.61 % and qDW-8 had the largest phenotypic variation explanation of 34.24 %. This study provided a good basis for molecular marker-assisted breeding of the hybrids between forage sorghum and Sudan grass.