To provide a shrinkage reduction agent for a hydraulic material which does not necessitate the combination with another admixture, is inexpensive, suppresses the decrease of the strength of a cured product, suppresses the occurrence of cracks of a concrete cured product by an excellent shrinkage reduction function, imparts an excellent water reduction function by a good compatibility with a water reducing agent, and further imparts an excellent freezing and thawing property because the quality entrained air can easily be improved by a defoaming agent and an AE agent, can improve the durability of a concrete cured product, and is highly versatile.

The shrinkage reduction agent for a hydraulic material is a compound represented by formula (1), wherein R1, R2 and R3 denote a hydrogen atom or a hydrocarbon group having 1-12C; AO denotes an oxyalkylene group having 2-6C; l, m and n denote an average addition molar number of an oxyalkylene group AO; l, m and n are 0, or 20 to 300; and all of l, m and n are not simultaneously 0.