Abstract: A three-piece umbrella cover structure having main rectangular cloth and two side-cloths is provided for use with an umbrella having a plurality of umbrella ribs. The main rectangular cloth has two stitch sides and four vertexes. Each side-cloth has one stitch side and a plurality of raised points corresponding to the stitch side. The stitch side has two ends, each having an indent defined therein. The stitch sides of the side cloths are combined with the stitch sides of the main cloth, respectively, wherein the indents are combined with the stitch sides of the main cloth to form indent seaming portions to provide pulling force for stretching the main rectangular cloth.

Abstract: A five-piece umbrella cover includes a primary cover and four secondary covers each securely attached to a corresponding one of the sides of the primary cover. The primary cover is square and may be composed of multiple auxiliary covers. The four corners of the primary cover are not attached to any of the secondary covers. Angles defined by ribs are not all the same.