Identification of quantitative trait loci （QTLs） and candidate genes related to resistant starch （RS） in rice grains is crucial for elucidating the genetic basis of RS accumulation in rice grains and facilitating the breeding of high-RS rice varieties. In this study， 139 rice germplasm resources were analyzed for their grain RS content across three consecutive growing seasons from 2021 to 2023. Using 255501 high-quality single nucleotide polymorphisms （SNPs） markers， a genome-wide association study （GWAS） was conducted using the FarmCPU model， revealing a total of 16 QTLs significantly associated with grain RS content. Among them， qRS-8-8 was simultaneously detected in all four environmental environments， explaining 33.99% of phenotypic variation， while qRS-11-1 was repeatedly detected in two environments， accounting for 14.06% of phenotypic variation. Through integrating gene function annotation， differential gene profiling， and haplotype analysis， two candidate genes related to grain RS content were identified within the QTL intervals. The gene LOC_Os08g28670 encodes a Bet v1-like special domain-containing protein， with previously uncharacterized function in rice， while LOC_Os11g44950 encodes a glycoside hydrolase family protein， with members of this family participating in physiological activities such as carbohydrate metabolism， growth and development， and stress resistance in plants. These findings provide a theoretical reference for further elucidating the genetic mechanisms of RS in rice grains and contribute to the genetic improvement of rice quality.