The present invention provides a pentosan polysulfate having a uronic acid content of 0.0% by mass to 6.0% by mass, preferably a pentosan polysulfate having a structure represented by Formula I:wherein each R represents a hydrogen atom, -COCH3 or -SO3X, and at least one R represents -SO3X, wherein X represents a hydrogen atom or a monovalent or divalent metal, and n represents an integer of 1 or more and 30 or less； a pharmaceutically acceptable salt thereof； or a pharmaceutically acceptable solvate of the pentosan polysulfate or of a pharmaceutically acceptable salt thereof. The present invention further provides a method for producing pentosan polysulfate, the method comprising the steps of depolymerizing a plant-derived raw material to obtain neutral xylooligosaccharide and sulfating the neutral xylooligosaccharide, in this order.
