Spindle whorls are a kind of spinning tools of crucially important in prehistoric period. Haidai region is one of the main historical and cultural areas of prehistoric China, and had a relatively developed textile handicraft production, where a large number of spindle whorls were unearthed, including many decorated ones. In order to make clear the uses of the decorated spindle whorls and the meanings of the patterns on them, the data of prehistoric decorated spindle whorls unearthed in archaeological sites of the period from Beixin Culture to Yueshi Culture in Haidai region of China were collected and analyzed, and the morphological data (dimension and shapes) of them were compared with that of undecorated ones. The patterns on the decorated spindle whorls were analyzed and classified, and the characteristics of the patterns in different cultural periods were studied, and based on this, the purpose of making decorated spindle whorls and the function and meanings of the patterns were discussed. The results showed that the range of morphological data of the decorated spindle whorls in Haidai region is consistent with that of undecorated ones belonging to the same period and unearthed in the same site, while compared with undecorated spindle whorls, decorated ones are more affected by regional culture and thus show different features from the ones unearthed in other archaeological sites belonging to the same cultural period. It is concluded that the most basic function of the decorated spindle whorls should be as practical tools for normal spinning production, and the patterns on them should have multiple meanings such as practical, decorative, distinctive and symbolic. The study of decorated spindle whorls can help us understand the prehistoric regional culture in Haidai region.