To identify quantitative trait loci （QTL） associated with rice grain appearance and cooking/eating quality， a recombinant inbred line （RIL） population consisting of 181 lines was developed by crossing indica rice 9311 and tropical japonica rice Cypress. A high-density genetic linkage map was constructed using resequencing data， and QTL mapping was performed based on evaluations of chalky grain rate， chalkiness degree， and amylose content in 2018 and 2019. A total of four QTLs for chalky grain rate， five QTLs for chalkiness degree， and six QTLs for amylose content were detected. A novel locus qCR5/qAC5， simultaneously affecting chalky grain rate and amylose content， was consistently detected within the chromosomal interval 18397268-20398241 bp on chromosome 5. In 2018 and 2019， the LOD values for chalky grain rate were 3.11 and 3.82 and the additive effects were -5.54 and -6.12， respectively. In 2018 and 2019， the LOD values for amylose content were 3.76 and 3.82， and the additive effects were -1.06 and -1.05， respectively. And the 9311 genotype of qCR5/qAC5 simultaneously increased both chalky grain rate and amylose content. Near-isogenic lines （NILs） with the 9311 genetic background were developed through backcrossing， and the genetic effects of qCR5/qAC5 were validated using BC₅F₂ segregation population. This locus accounted for 20.9% of the phenotypic variation in chalky grain rate and 18.6% in amylose content. These findings lay a solid foundation for the fine mapping of qCR5/qAC5 and hold significant implications for genetic improvement of rice grain quality.