The term UHPC refers to a relatively new class of advanced cementitious composite materials whose mechanical and durability properties surpass those of conventional concrete. Because of the high compressive strength (> 150 N/mm2), it is possible to run very slender and thin-walled constructions. The field of application is not only limited to the classical constructions, but also can be applied for the mechanical machines, objects, and in the design area. The dense microstructure of concrete leads to a particularly high resistance to physical and chemical attacks, and makes UHPC an ideal material to use in aggressive environments. In order to achieve these outstanding features, a careful selection of raw materials is necessary. The mixture composition is essentially different from that of a normal concrete. Due to the high proportion of fine-grained particles, the mixing process is also of great importance. Especially along with the vacuum mixing process, both the fresh concrete and the hardened concrete properties can be influenced. From the concrete technological point of view, the extremely low water-cement ratio (generally well below 0.3) plays a fundamental role in dense concrete matrix. In order to allocate a good workable consistency (mostly flowing) to UHPC, the use of highperformance superplasticizers is necessary. Currently, the superplasticizers based on polycarboxylate ethers (PCE), posses the best plasticizing effect. However, it is known that these superplasticizers in high doses, as they are necessary for UHPC, greatly retard the hardening of the concrete. However, to achieve a significant compressive strength after a few hours up to a day, the components must be chosen in such a way that the delaying effect of the superplasticizer is compensated. In this study, the essential parameters of UHPC were varied in an extensive series, and the effect on the early strength development were characterized by flexural and compressive tests.