The report presents studying result on the spatial and seasonal distribution of shrimp larvae at three typical coral reefsites of Cat Ba - Ha Long area as part of the KC.09.26/06.10 project. There were three genera, seven families belonged to three infraorder have been identified in the study area. Family Alpheidae have the highest number of individuals to occupies for 41.02 percent of the total number of shrimp larvae. The family Pasiphaeidae contains the lowest number of species (0.47 percent) and next to family Palaemonidae (0,86 percent) that occupies for less than 1 percent. There was the distribution of the number of individuals varies among reef sites. At Coc Cheo coral reef, the density of shrimp larvae is the highest (472.5 individuals /100m3), lowest value is found at Cong Do rec!j (60.5 individuals /100m3). Conversely, the species diversity of the shrimp larvae at Coc Cheo reefis lowest (4 families) and highest values at the Cong Do reef (7 family). The density of shrimp larvae seasonally changes but varies among reef sites. In the Ba Trai Dao and Coc Cheo reeft, the composition and number of individual larvae in the rainy season is higher than that of dry season but at Cong Do reef is conversely.