Plankton and marine snow, as the productive base of the marine ecosystem, play a crucial role in the marine food webs and carbon cycle. With the recent development and increasing application of the in-situ Imaging system, it brings us an opportunity to conduct the qualitative and quantitative in situ observation. It could provide us real-time information on the characteristics of their community structure and spatio-temporal distribution in the marine water column，and help us better understand the biodiversity, the bio-ecological system and their impacts on the marine carbon cycle, or even on the climate change. However, so far, few technical and scientific applications are carried out in the East China Sea (ECS) due to the environmental complexity, such as the high turbidity range and severe biofouling. To achieve our scientific purpose, the continuous particle imaging and classification system (CPICS) was applied to obtain the real-time characteristics of the community structure and distribution of phyto- and zooplankton in the ECS. The impacts on the imaging quality by the water turbidity were verified in the lab in advance and it showed that CPICS may perform within the turbidity range of 0-50 NTU. By the casts at 4 stations along the transect in ECS in July 2019, the profiling data showed that besides substantial particles the targeted organisms mainly were large to medium-sized plankton, belonging to 6 disciplines and 6 classes, and it showed that Noctiluca scintillans was the dominant species, consistent with the species identification and counting results from the collected water samples. Furthermore, To achieve the long-term monitoring data, CPICS was equipped with the buoy deployed in ECS from September 2019 to April 2020. Besides substantial particles and bubbles, the targeted organisms were composed of a few microplankton (90-200μm),  medium-sized plankton (200 μm-2 mm) and large- sized plankton (2-12 mm). The dominated phytoplankton was replaced by the Trichodesmium with morphology in different growing stage in October 2019. However, the long-term variation of imaging quantity showed that it might be effected by the severe biofouling. Therefore, by using of CPICS, the seasonal variation of dominant species and the morphology of phytoplankton were displayed, providing an insight on real-time monitoring the algae blooming and the role of biological pump in the marine carbon cycle.