Abstract: The bioassay of freshwater sediment toxicity is described. The tested sediment can be got by sampling and/or spiking and the storage of sediment affect bioavailability. Whole sediment, interstitial waters, elutriates are usually used as test phase. Among of them, the interstitial water is the appropriate test phase of sediment toxicology, and it is recommended to collect by centrifugation. Meanwhile, use of several species is encouraged to increase comparability of results.