Pi25, rice blast resistance gene, is a broad-spectrum resistance gene with high genetic transmission capacity. In this paper, the indica rice parent BL 27 with Pi25 was as the gene donor and was introgressed into Zhenda B, the maintainer line of the CMS line ZhengdaZhenda A, and then improved new maintainer lines with homozygous gene of Pi25 and agronomic traits similar to the ZhengdaZhenda B was successfully developed. The improved maintainer lines were crossed and backcrossed with CMS line ZhengdaZhenda A for transformation of CMS line. By molecular marker-assisted selection combined with phenotype-based visual selection, three improved CMS lines were developed with homozygous geno-type of Pi25, overall agronomic traits and flowering habit similar to the ZhengdaZhenda A. By artificially inoculating 22 representative blast isolates collected in Fujian province, the resistance frequency of 3 improved CMS lines and 15 hybirds were found to be 95.45% to 100% and more than 75%, respectively, whereas that of original control, Zhenda A and its hybrid combinations derived from the original control, ZhengdaZhenda A was only 54.55% and its hybirds were 40.91% to 63.64% respectively. Three improved CMS lines also displayed high resistance to leaf blast ( level 0 ) and panicle neck blast ( level 0 ) when grown in the epidemic areas field, whereas the original control was susceptible to leaf blast (level 5) and panicle neck blast (level 7) . Those 15 hybrid combinations displayed high resistance to rice blast. Furtherly, the results of comparison of yield, agronomic characters and quality among 15 hybrid combinations showed that Zhenda A-Pi25-3 improved CMS line showed best comprehensive characteristics and was backcrossed with improved maintainer line ZhengdaZhenda B-Pi25-3. Thus a new CMS line was bred with strong blast resistance, good combining ability, population uniformity and the stability characteristics, named for the 157A. The results indicated that the Pi25 gene could completely express its dominant resistance in background of CMS line Zhenda A during different growth stages, and also showed higher levels of resistance in backgrounds of the hybrid combinations derived from different restorer lines, suggesting its immense breeding value in blast resistance improvement for hybrid rice. Compared with Zhenda A, the 157 A showed blast resistance increased significantly, but also fundamentally retained excellent properties of high combining ability of CMS line, and provided a new male sterile germplasm for breeding of hybrid rice with high yield, high quality and disease resistance.