Production method of the color stable high water absortion power polymer, and the said polymer which possess long term color stability is disclosed. The color stable high water absortion power polymer is produced substantially under non- existing of the persulfate salt, at the same time is disclosed to the ultraviolet ray of the low dose. As for the high water absortion power polymer which is obtained, regarding temperature and the humidity which are raised, it is resistance in deterioration of color during period of the storage which is extended.長期間色安定性を有する色安定高吸水性ポリマー、および該ポリマーの製造方法を開示する。色安定高吸水性ポリマーは、実質的に過硫酸塩の不存在下に製造され、かつ低い線量の紫外線に曝露される。得られる高吸水性ポリマーは、高められた温度および湿度においても、延長された貯蔵の期間中の色の劣化に抵抗性である。
