The global aquatic product industry is undergoing a strategic shift towards "quality-centric and efficiency-driven" development, with high-quality seafood at the core of market demand. As the most productive marine shellfish in China, oyster yield reached 7.252 million tons in 2024. Within this industry, glycogen content is a crucial determinant of oyster sweetness, flavor, and texture, while also playing vital roles in energy metabolism and stress tolerance. Consequently, it has become a key target trait for germplasm innovation. Substantial genetic breeding research has been conducted on the Pacific oyster (Crassostrea gigas), with established heritability estimates for both growth traits and glycogen content, demonstrating significant potential for genetic improvement. In contrast, the Jinjiang oyster (Crassostrea ariakensis), an economically and ecologically important species in China"s estuaries, lags considerably behind. Genetic parameter data for C. ariakensis are scarce, especially for growth traits, and estimates for glycogen content are entirely absent. This knowledge gap severely hinders the development of new, high-quality C. ariakensis breeds. To enable effective selective breeding for high-quality, fast-growing strains, this study aimed to systematically estimate the genetic parameters of shell height, shell length, and glycogen content in C. ariakensis.