The　effects　of　triethanolamine　on　the　compressive　strength　and　setting　time　of　fly　ash　cementitious　materials,　slag　cementitious　materials,　and　limestone　cementitious　materials　were　investigated.　The　results　show　that　the　dosage　of　0.04%　of　triethanolamine　can　significantly　improve　the　3d,　7d　and　28d　compressive　strength　of　fly　ash　cementitious　materials.　It　possesses　less　impact　on　the　setting　time.　The　dosage　of　0.04%　of　triethanolamine　can　significantly　improve　the　3d　and　7d　compressive　strength　of　slag　cementitious　materials　while　the　effect　of　late　strength　is　not　obvious.　It　extends　the　initial　setting　time　and　the　final　setting　time　is　not　changed,　which　has　retarding　effect.　The　results　of　hydration　heat　and　XRD　show　that　triethanolamine　extends　the　induction　period　of　cement　hydration,　and　gypsum　is　exhausted　in　advance　during　the　hydration　process.　Triethanolamine　promotes　the　transformation　of　AFt　to　AFm　and　there　is　no　effect　on　the　type　of　hydration　products.　©　2017　Trans　Tech　Publications,　Switzerland.