Dechloranes, including dechlorane 602 (Dec 602), dechlorane 603 (Dec 603), dechlorane 604 (Dec 604), dechlorane plus (DP, including syn- and anti-DP) and mirex, were determined in marine food web from Dalian Bay, Northeast China to investigate their occurrence andtrophic transfer. In all organisms, the detection rates were Dec 602 (99%) > mirex (95%) > Dec 603 (92%) > anti-DP (91%) > syn-DP (82%) > Dec 604 (9.6%). The concentrations were 0.92–16 ng/g lipid weight (lw) for mirex, 0.53–2.3 ng/g lw for syn-DP, 1.1–4.5 ng/g lw for anti-DP, 0.19–5.0 ng/g lw for Dec 602, 0.26–1.9 ng/g lw for Dec 603 and 0.020–0.33 ng/g lw for Dec 604. Significant positive relationships (p < 0.0001) were observed between lipid normalized concentrations and trophic levels for mirex (R2 = 0.80) and Dec602 (R2 = 0.82) in food webs, with the calculated TMFs values of 3.09 and 3.39, respectively, indicating the trophic magnification potential of these compounds. For syn-DP, anti-DP, Dec 603 and Dec 604, the similar significant relationships were not found, suggesting that these chemicals do not trophic magnification nor trophic dilution in the food web. With low log KOW values for mirex (7.01) and Dec 602 (8.05), these two compounds have the highest magnifications potentials, while the magnification potential of Dec 603, Dec 604 and DP dramatically decreased because of their extremely big log KOW values (higher than 10). The observed fractional abundance of anti-DP (fanti) ranged of 0.58–0.69, closing to the one in Chinese industrial products, indicating DP isomers had not undergone significant differences of physicochemical or biological process in the studied food web.