Abstract: Tris(2-carboxyethyl)phosphine (TCEP) is a new endocrine disruptor (Endocrine Disrupting Chemicals, EDCs), which can cause strong biological toxicity at low doses. With the increasing use and sewage of TCEP entering the sea through rivers, its accumulation in seawater and its threat to aquatic organisms are increasing. Turbot (Scophthalmus maximus) is a common large-scale mariculture fish, the TCEP accumulated in seawater will affect the development of its aquaculture industry. By studying the effects of different concentrations gradient and different stress times of TCEP on turbot, LC₅₀ at four time points were 190.76 mg/L (24 h), 159.94 mg/L (48 h), 140.70 mg/L (72 h) and 110.71 mg/L (96 h), and safe concentration (SC) was 33.60 mg/L. This provided a basis for healthy culture and toxicologic research of the burbot. Using real-time fluorescence quantitative PCR technique, the relative expression levels of two cytokines, histocompatibility complex α (MHC-II α) and tumor necrosis factor α(TNF-α), were analyzed. It was found that the expressions of these cytokines were up-regulated after TCEP treatment; With the increase of mass concentration of TCEP, especially it reached 47.69 mg/L ( \frac14 LC₅₀), the changes of gene expressions were more obvious; While the stress time was more than 12 h, the gene expressions showed a trend of increasing first and decreasing afterward. It showed that TCEP can cause acute injury to the immune system of turbot. This study can provide the reference for both the healthy culture of turbot and a molecular marker for detection of environmental pollutants.