Leaves are the main organs for photosynthesis in rice (Oryza sativa L.), and leaf morphology is the primary factor affecting the photosynthetic efficiency of rice plants. Continuously exploring genes that control leaf curling and revealing their genetic mechanisms, could provide optional genetic resources for cultivating ideal rice varieties with moderately curled leaves. In this study, the natural rolled leaf mutant rl76 was used as the material to carry out agronomic trait investigation, leaf cellulose, chlorophyll content determination and tissue morphology observation, and the rice GSR40 K chip technology was used to locate the RL76 rolled leaf gene. Phenotypic identification results indicated that there was no significant difference in the leaf rolling phenotype between the mutant rl76 and the wild type at the seedling stage, both of which showed slightly rolled. From the tillering to maturity stage, the leaves of rl76 were extremely rolled into shallot-like and erect, while the leaves of wild type were flat and slightly drooping. Compared to the wild type, the leaf rolled index of rl76 increased significantly, plant height and effective tiller number decreased significantly, and there was no significant difference in leaf width, flag leaf length and panicle length. The chlorophyll content was significantly higher than that of the wild type, the carotenoid content was not significantly different, nevertheless, the cellulose content and lignin content were lower than those of the wild type. The leaf structure by paraffin sectioning was observed that the rl76 mutant leaf cavity disappeared, the development of the thick-walled cells on the abaxial surface was defective, and the area and number of vesicular cells decreased. Genetic analysis shows that the rolled leaf trait was consistent with the incomplete dominant single gene inheritance pattern. By using rice GSR40K chip technology, the rl76 gene was preliminarily localized in the region of 12.179-16.436 Mb on chromosome 9. With the extreme 949 leaf-rolled plant in the F₂ population, the rolled leaf gene was further fine mapped on the chromosome segment of SSR markers T5904-7 and T5904-9 with a physical distance of 30.26kb on chromosome 9. This chromosome segment contains three annotation genes, among which LOC-Os09g23200 is a gene SLL1 that has been reported to regulate rice leaf curling by regulating the development of leaf distal surface cells. Therefore it is speculated that the rolled leaf phenotype of the mutant rl76 may be regulated by the SLL1 gene. In summary, the rolling leaf phenotype of the rl76 mutant was resulted from the abnormal development of bulliform cells and abaxial thick-walled cells regulated by an incompletely dominant single gene on chromosome 9.