Effects of the variations of pH value，temperature and colloidal particles in extractant solutions on heavy metals speciations were investigated by the sequential extraction procedure（SEP） used in anoxic sediments at mariculture zone.The results showed that a slight increasement of pH values of extractant solutions lead to the decrease of concentrations of Cd and Zn in Step1 of SEP for acid soluble speciations，However，the obvious variations of pH values of extractant solutions had no significant influence on heavy metals speciations in Step2 for reducible fraction and Step3 for organic matter bound fraction（except Pb），respectively.The temperature of extractant solutions were slightly increased in Step1 and Step2 and decreased in Step3 due to the different reaction thermodynamics in extraction steps of SEP，and the variations of temperature（＜2.5 ℃） had little effects on the concentrations of heavy metals speciations.Due to adsorption，the formation of colloid in Step1，Step2 and Step4 resulted in the decrease of Cd，Zn and Cu concentrations，respectively.However，the formation of colloid was controlled by extractant in Step3.Therefore，controlling pH and colloid in extractant solutions were available to improve the stability and accuracy of extraction results when SEP was applied to evaluate heavy metals speciations in anoxic sediments.