The influence of shrinkage -  reducing agent on cement paste structural formation was studied by the analysis of drying -  shrinkage, resistivity and compressive strength. The results showed that: from the view point of drying -  shrinkage, the compatibility of shrinkage - reducing agent and water -  reducing agent is well, and is not affected by retarders or accelerators; from the view point of compressive strength, the compatibility of shrinkage -  reducing agent and water -  reducing agent is faint, and the compatibility of shrinkage -  reducing agent and retarders or accelerators is related to the kinds of retarders and cations. Ion solution is restrained initially by shrinkage -  reducing agent, also the cement hydration retarded slightly, the stage of structural formation accelerated, but the cement strength dropped.