It is well known in Japanese archaeology that potters of Latest Jomon Culture have produced various kinds of vessels, such as jars, bowls, plates, spouted vessels and so forth, especially in the Latest Jomon Culture in North Eastern Japan with the so-called Kamegaoka type of pottery. In this paper, the writer tries to work out the development and degeneration of the Kamegaoka pottery complex, focusing upon the integration and specialization of its' traits and taking up the spouted vessel as a typical example, which shows the most Complicated stylistic variations of shapes and designs among Kamegaoka pots. These spouted vessels can be classified chronologically into three subcomplexes; Early (Obora B and B-C type), Middle (OboraC_1 and C_2) and Late (Obora A and A'). The stylistic variation shows it's highest complexity in the Early subcomplex. As shown in Fig. 2, at least four characteristic vessel shapes can be seen among the spouted vessels. It is remarkable that all of the spouted vessels in the Early subcomplex have different shapes than those produced before and after the Early subcomplex, which tended to have jar-shaped bodies. In other words, the potter made primarily jar-shaped bodies in the preceding Later Jomon Culture, developed four new vessel shapes in Early and Middle complexs of the Latest Jomon Cultures and returned to the previous jar-shaped bodies in the Late subcomplex. It is clearly recognizable that this morphological change of vessel shapes is correlated with the developmental and degenerative trends of the Kamegaoka pottery complex as a whole. The writer suggests that this should be explained in terms of changes in the potters' productive system.