PURPOSE: A trench for indoor floor drainage is provided to improve convenience for maintenance and repair and enable installation corresponding to a drainage passage, since both sides and a floor panel are formed of unit panels to correspond to a U-shape drain path. CONSTITUTION: A trench for indoor floor drainage comprises an expandable trench body(2) and a trench cover(3). The expandable trench body is formed of a wall panel(20) and a floor panel(21). The wall panel connects to a coupler the longitudinal direction of a drainage passage(A). The floor panel forms level difference from a drain outlet to the longitudinal direction of the drainage passage. The trench body is mounted on the opening and is parallel to the indoor floor.
