Sedimentation model testes were carried out on dredged slurry treated by calcareous flocculants at high initial water content. The influences of calcareous flocculants on the self-weight sedimentaiton characteristics of dredged slurry were discussed based on the test results. The results show that the settling of dreged slurry with calcareous flocculants undergoes flocculatin, hindering settling and self-weight consolidation. The addition of calcareous flocculant would result in a decrease of the settling time, while the stable settlement amounts induced by self-weight sedimentation vary with the properties and dosages of calcareous flocculants. For the CaCl2, it mainly affects the self-weight sedimentation characteristics of dredged slurry by the ion exchange and electrical neutralization. Unlike the CaCl2, the effects of Ca(OH)2 on the self-weight sedimentation characteristics of dredged slurry is primarily controlled by flocculantion at the earlier stage, and then by the pozzolanic reaction, resulting in a substantial reduction of the stable self-weight settlement value for dredged slurry pretreated with Ca(OH)2.