PURPOSE: A construction method of a concrete building is provided to reduce a construction period by reducing the placing time of concrete mortar to build each floor of slabs and walls. CONSTITUTION: A construction method of a concrete building is as follows. A lower wall(1b-2) is built so that the lower part of a vertical-form connecting pillar(4) is buried at the upper end of the lower wall and the upper part of the lower wall is protruded by a given height. A plurality of horizontal-form support members(5) are installed to form the same height on both sides of the upper part of the lower wall. A horizontal form(2) for constructing a slab is installed with the horizontal-form support members and a plurality of supports. A vertical form(3) for constructing a wall is installed on the slab-constructing form.
