Blended cement using supplemental cementitious materials such as fly ash and blast-furnace slag, which leads to reduction of CO2 emission in the process of cement production, has been extensively used in many countries.However, in Japan, the consumption of blended cement accounts for only 20 %.Especially, use of fly ash cement for concrete structures is rare except for dam concrete.This is mainly because strength development of concrete with fly ash cement is slower at early ages compared to ordinary Portland cement.The purpose of this study is to propose fly ash cement which is expected to be used for general concrete structures including reinforced concrete buildings.In order to improve strength development of fly ash cement at early ages,samples of clinker with high C3S content up to 72 %, by Bogue equation, were manufactured at an actual cement plant.Strength development of concrete with fly ash cement using the high C3S clinker was experimentally investigated.Influence of curing temperature on strength development was also investigated.Tendency of shrinkage cracking due to dying was investigated with uniaxial restraint tests.It was proved that early-age strength development of fly ash cement was significantly improved by using the high C3S cement especially at low temperature.Shrinkage cracking resistance was also improved by adjusting SO3 content compared with ordinary Portland cement and conventional blended cements.