Abstract: The drifting and dispersal process of fish larvae in rivers is closely related to external environmental factors. This process influences individual growth and survival, thereby determining population replenishment, making it a key focus of research. In this study, synchronous sampling of drifting larvae and habitat factors was conducted in the Shashi section of the Changjiang River from 2018 to 2019, aiming to investigate the composition and spatial distribution of drifting larvae and their relationship with habitat factors. The results showed that: ① The two-year study revealed that the larval species collected in the Shashi section mainly included Pseudolaubuca, Hemiculter sp., Squalidus argentatus, Saurogobio dabryi, Rhinogobius sp.and the four major Chinese carps. The developmental stages of the larvae were primarily concentrated in the fully developed eyes and rudimentary swim bladders.Pseudolaubuca, Hemiculter sp.covered all developmental stages and exhibited the widest body length ranges.② In terms of spatial distribution, larval density was higher near both riverbanks and lower in the middle of the river, but no significant difference was observed between the central and littoral zones. The coefficient of variation indicated that the location of the sampling section had a significant effect on the density of fish larvae.③ The random forest model showed that the distribution of total larval density across different sampling sections was mainly influenced by six habitat factors: phytoplankton Shannon diversity index, water temperature, pH, water level, discharge, and distance from the riverbank. The model demonstrated good predictive ability. Future research should focus on the interrelationships and differences between different species and developmental stages of fish larvae and multi-habitat factors, identify species-specific preferences for suitable habitats, and clarify the early fish resource replenishment mechanisms under hydrological regulation, so as to guide reasonable reservoir ecological operation and river management measures.