, which occurs in the coastal waters of China, including the Yellow and East China Seas, is a delicious seafood and has great economic value. In the past few years, resources have rapidly declined, as a result of the use of a smaller net mesh sizes of the fishing gear, which has resulted in large numbers of fish fry being caught. To better develop and protect resources, the goal of this study was to determine the differences in selectivity of various mesh sizes and hanging ratios for were collected by using a simulated cover-net method in a flume tank. A logistic curve was fitted as a selectivity model to obtain selective curves of different mesh sizes and hanging ratios. Selective parameters were estimated by MLE (Maximum Likelihood Estimate). The results indicated that the selection length (Sebastes schlegelii when the mesh sizes were 63 mm, 82 mm, and 93 mm. Selection rangers (SRs) were 2.05, 3.6, and 3.85, and selection factors (SFs) were 2.83, 2.72, and 2.70, respectively. The SR increased with an increase in the mesh size, whereas the SF decreased. When three groups of hanging ratios (0.5, 0.6, and 0.707) for 82 mm mesh size were chosen to study the impact of hanging ratios, the respective of s were 21.47 cm, 23.90 cm, and 22.02 cm, SRs were 3.23, 3.6, and 3.38, and SFs were 2.65, 2.91, 2.68, respectively. With an increase in the hanging ratio of meshes, the , SR, and SF increased first and then decreased, and obtained a maximum value at the hanging ratio of 0.6. It was concluded that the suitable size of fishing gear for protecting masked greenling resources was a 7 cm mesh size and a hanging ratio of 0.6.