Xinzhou section is a typical stream-sandbank habitat in the lower reaches of the Yangtze river. In order to understand the larvae and juvenile fish assemblage feature in this section, Structure, dominant species, abundance and spatial-temporal distribution were investigated, from April 15 to August 4, 2018, and the relationships with environmental factors were probed at the same time. 121246 larvae and juvenile fish were identified, belonging to 6 orders, 8 families and 34 species. 79338 larvae and juvenile fish were captured in the south branch, accounting for 65.44% of the whole species; and 41908 in the north branch, accounting for 34.56%. Among the spawning types, fish species with pelagic eggs (16) were dominant; whereas, fish with floatability eggs taken the largest number, which were 92623 individuals. was the first dominant species and other dominant species are Rhinogobius giurinus. The diurnal variation trend of abundance in north and south branch were consistent. The larval and juvenile fish abundance reached its peak level (2001.28 ind/100 m³) on July 13, which showed a high correlation with water level. The abundance of inshore sampling points was higher than that of mid-channel, and the abundance of south branch was higher than that of north branch. Redundancy analysis found that water level, water temperature, turbidity and transparency are the main environmental factors affecting the assemblage structure of larval and juvenile fish. Water level is the main positive correlation factor. The cluster analysis divided the 6 sampling points into 3 groups, showing significant differences in assemblage structure of larval and juvenile fish (=0.017). The results showed that there was a significant influence on the distribution of larvae and juvenile fish in Xinzhou section, and the breeding conditions of fish in the south branch were better. The results provided the scientific data of the early fish resource in Xinzhou section and the protection strategy of fish resource in the lower reaches of the Yangtze River.