Abstract: Molecular marker-assisted selection can achieve accurate selection of target genes quickly and provides an effective tool for molecular breeding. Using restorer line Shuhui 527 as receptor parent and IRBBL23, which carrying Xa23, a resistance gene to bacterial blight, as donor parent, the broad-spectrum and persistently resistant gene Xa23 was introduced into the restorer line Shuhui 527 by crossing and backcross breeding combined with molecular marker-assisted selection, 22 improved lines containing Xa23 gene were obtained. A New Restorer Line R527-Xa23 with high resistance to bacterial blight was screened by inoculating the improved strain P6. The agronomic traits of hybrid combinations from R527-Xa23 and sterile lines Gu A, Ⅱ-32A and Tefeng A were further investigated. The results showed that the improved combinations of R527-Xa23 and Shuhui R527 had similar agronomic traits in panicle length, number of panicles per plant and 1000-grain weight, which indicated that the restorer line R527-Xa23 had broad application prospects in breeding hybrid rice combinations that resistant to bacterial blight.