To study the composition, abundance, biomass, and spatial distribution of meiofauna and their relationship with environmental variables, meiofauna samples were collected from the Bohai Sea (37.0°-40.0°N,118.0°-122.0°E) in June 2011 and November 2011 by R/V ‘Dongfanghong Ⅱ’. The results showed that meiofauna and nematode abundance was lower in the Yellow River estuary adjacent water and near shore water. Results also showed that meiofauna abundance differed between the two cruises, with higher abundance in June (1012.7±519.1) ind/10 cm² compared to November (829.5±385.8) ind/10 cm². In contrast, meiofauna biomass was higher in November (661.3±310.9) μg dwt/10 cm² than in June (570.8±307.6) μg dwt/10 cm². A total of 18 meiofaunal groups were identified during the two cruises. The dominant taxonomic group was free-living marine nematodes, constituting 95.0% and 90.3% of total meiofauna abundance in June and November, respectively. Other important groups were benthic copepods, polychaetes, kinorhynchs, and ostracods. Of these, polychaetes exhibited higher abundance in November compared to June, suggesting significant seasonal variation. Analysis of meiofaunal vertical distribution indicated that 93.5% and 91.1% of the meiofauna was distributed in the top 5 cm of the sediment in June 2011 and November 2011, respectively. No seasonal vertical distribution differences were detected. Correlation analysis between meiofauna abundance and different environmental variables showed that abundance was negatively correlated with sediment medium grain size, water content, and sediment organic matter content, suggesting that these parameters were the most important factors affecting meiofauna abundance and distribution in the study area. The results of BIOENV analysis indicated that the combination of water depth and organic matter content correlated best with the meiofaunal assemblage. After comparing the present data with meiofaunal historical data from the past 30 years in the Bohai Sea, we observed that total meiofauna abundance and biomass increased gradually over that period. However, while meiofauna and free-living nematode standing stock increased, copepod standing stocks decreased in the past 30 years.