The present article hopes, by examining the rhymes of the Shih ching, to offer a modest contribution to the study of the formation of the anthology and to suggest a criterion for distinguishing the relative age of the poems in it. As is well known, the rhymes of the Shih ching provide invaluable data for the study of the sound system of archaic Chinese. It cannot be too strongly emphasized, however, that they do not represent the unified sound system of any single period, but rather reflect changes that took place over a considerable period of time. The author has studied the word lai 來 in the instances in which it functions as a rhyme, and has discovered that these fall into two categories. The first comprises the uses of the word in odes ＃ 30, 33, 66, 91, and 217; the second comprises the uses in odes ＃ 167, 168, 169, 171, 203, 242, and 263. The former represent rhymes in the level tone, while the latter represent those in the entering tone or the departing tone (in the very early period, in terms of the final the departing tone formed a single category with the entering tone). The relationship between the two groups of rhymes is quite clear and gives concrete evidence of the way in which the final of the entering tone was gradually lost. It will be noted that these two groups of lai rhymes correspond almost exactly to the Kuo-Jeng and the Ta-ya and Hsiao-ya sections of the anthology respectively. Since the lai rhymes in the entering tone are older and these in the level tone more recent in date, this would serve to indicate something about the relative dates of the Kuo-Jeng and the Ta-ya and Hsiao-ya sections. Such a theory of relative dating, it may be noted, differs markedly from that suggested by some scholars such as Masaaki Matsumoto. The writer hopes that his suppositions will be verified by further research and that he may be able in this way to offer a new method for determining the relative age of the various poems and sections of the anthology.