The Ti-extracted slag is a by-product of Ti-bearing blast furnace slag after further extraction of titanium， and it has potential cementitious reactivity. However， due to the presence of chloride ions， its utilization in construction is limited. Therefore， further dechlorination treatment is needed. In this study， the effect of Ti-extracted residues with different dechlorination methods on the properties of cement paste was investigated. Results showed that the addition of Ti-extracted slag can reduce the fluidity of cement paste. The presence of chloride ions can shorten the setting time of the paste， and a higher amount of the slag resulted in a shorter setting time. At the same content of the residues， the shortening degree of setting time of the slag under the different dechlorination methods was obtained as follow： non-dechlorinated slag> water-washed slag> calcined slag. No obvious change in the compressive strength of the paste was observed by adding 20% Ti-extracted slag， but further increase in the content can probably reduce the strength. Chloride ions in the Ti-extracted slag were combined in the Friedel salt of the cement paste. After adding Ti-extracted slag， the stretching vibration peak of the Si—O bond shifted to a lower wavenumber. 10%~20% of Ti-extracted slag in the cement paste is recommended.