Abstract: Based on the mariculture statistics from 2016 to 2020 and the progress of the three-year plan to fight pollution of the Bohai Sea, the trend and effectiveness of mariculture in China’s coastal waters and the Bohai Sea region were analyzed. The results show that the three-year plan has achieved positive results in mariculture, and the mariculture area of provinces around the Bohai Sea has decreased by 7.7%, In the Bohai Sea, more than 70 thousand hectares of mariculture that is not meet the requirements of management have been renovated, and the fishing production in the Bohai Sea region has decreased by 40.7%. However, compared with the national coastal situation, the effect of mariculture around the Bohai sea is not outstanding. While the area of mariculture has decreased, the output has increased by 8.8% and the output value has increased by 22.2%, the provinces around the Bohai Sea reduced the output by 0.6% and increased the output value only by 4.8%. The ecological and environmental problems are still prominent. Nearly 50 thousand hectares of mariculture in the provinces around the Bohai Sea are located within red lines for ecological protection. The majority of wastewater from mariculture is discharged directly. It is urgent to strengthen the supervision and management of mariculture in the Bohai Sea.