Abstract: Short-chain chlorinated paraffins (SCCPs) are persistent organic pollutants (POPs) that have been added in recent years, and their toxic effects have been limited and it is difficult to effectively assess their ecological risk. In this study, the toxic effects of SCCPs on typical zooplankton and phytoplankton were explored through plankton [1]toxicity tests, data collections and statistical analysis. The acute and chronic toxicity tests of SCCPs on 4 species of algae, Daphnia magna and Brachionus calyciflorus were carried out and the sensitivity of each species was assessed. The test data were sorted out and the literature data were collected and screened, and the long-term water quality criteria for aquatic organisms (LWQC) of SCCPs was derived by using the species sensitivity distribution curve (SSD) method, which is of great significance for ecological risk assessment and control of SCCPs in China. The toxicity test results were mainly as follows: ①The growth inhibition test results of 4 algae showed that Chlorella pyrenoidosa was the most sensitive to SCCPs, and the Scenedesmus quadricauda was the least sensitive. ② The EC₅₀ of SCCPs to Daphnia magna at 24 and 48 h were 37 and 9.5 μg/L, respectively. The results of chronic toxicity test showed that SCCPs inhibited the growth and reproduction of Daphnia magna obviously, the lowest observed effect concentration (LOEC) was 6 μg/L, and the no observed effect concentration (NOEC) was 4 μg/L. ③In the chronic toxicity test of Brachionus calyciflorus, SCCPs of the highest concentration group (80 μg/L) had a serious effect on the reproduction of Brachionus calyciflorus, and the NOEC of SCCPS to Brachionus calyciflorus was 10 μg/L. ④ Combining test and literature data, comparing the sensitivity of various species, the most sensitive to SCCPs is Daphnia magna, followed by rotifers, fish and Chironomus tentans, and algae are relatively insensitive. The LWQC of SCCPs obtained by SSD curve extrapolation is 1.92 μg/L.