Disclosed is a drainage canal structure, and in particular is a prefabrication type drainage canal structure which makes it possible to prevent a transformation and disengagement of a drainage canal in such a way that a plurality of drainage canal bodies each equipped with a waveform reinforcing unit are assembled in series, and a protection net is arranged over the drainage canal bodies which are buried underground, and a side reinforcing unit is installed into the ground so that a bottom foundation can be expanded, and the drainage canal bodies can be fixed in place on the ground. Trees, gravels, etc. can be prevented from penetrating into the drainage canal bodies thanks to the protection net. The drainage canal structure with an increased self-weight can be provided, which can keep it in place. Work and construction time can be saved because the drainage canal structure can be manufactured on the spot.