Concerning the constructions formed by the echoes of the numerals “Yi” (一) and “Ban” (半）, four-character phrases, such as “一时半会” and “一知半解”, which generally means small quantity, used to draw most attention. The research objects selected in this paper are quite different. Firstly, they are not confined to the four-character structure in form, as shown in such constructions as “一部民国史，半部在浙江” and “一座开封城，半部民国史”, which are typically structured in a couplet with two five-character lines. Secondly, it is intended to emphasize the importance of a certain part in a whole. The first example mentioned above is characterized by the whole preceding the part, while the second is characterized by the part preceding the whole. In both cases, under the premise that the frame of “一……，半……” remains unchanged, the nouns in the front and back of each can also be reversed as “一个浙江省，半部民国史” and “一部民国史，半部在开封”，which basically mean the same as the original expressions. The fixed items in this construction are the corresponding numerals “一”and “半”, called relational characteristic words in this paper, They are initially positioned in the front section and in the back section respectively, with “半” at the core of the construction, as a key indication of the sentence-internal relationship. In some examples, “一” can be omitted, but not “半”. Another key to this construction is the nouns included in the first section and in the second section respectively. Drawing on the “Figure-Ground” model in the image schema theory of cognitive linguistics, this paper clarifies the two conceptual categories of the nouns that represent the whole (hereinafter referred to as N-whole) and the nouns that represent part (hereinafter referred to as N-part), and summarizes in one sentence the relationship between the nominal phrases in this construction: the N-whole includes but is not confined to the N-part with the latter meaning less than a half of the former, which explains why raising it to the status of “(one) half”of the whole emphasizes the importance of its status as well as its implication of exaggeration. “一” and “半” in this construction should not be interpreted literally. All this shows that the linguistic logic is not necessarily the same as the mathematic one. This construction, focused on the thinking pattern of contrast, highlights the importance of “part” relative to “whole”, through a comparison between N-whole and N-part as well as that between “一” and “半”. On the basis of a large collection of examples, the “一……半……” construction can be classified into two types: one featuring the whole preceding the part and the other featuring the part preceding the whole. A conclusion that can be reached through a study from the perspectives of syntax, semantics and rhythm is as follows: The “一……半……” construction discussed in this paper is a number-involving, antithetical, and cultural construction. The first two of these three characteristics have been discussed above, and here we will focus on the third one. The cultural connotation of this construction includes not only the number culture and the antithesis culture, but also the psychological culture of language users. This construction is rich in humanistic connotations, considering the trade, regional and temporal nature of the referents of the nouns in this construction. Moreover, the nouns in this construction mostly contain the Chinese character “史” due to the tendency of the Chinese people to value the historical status of people and things when passing judgment on them. Correspondingly, the measure words in such a construction are most frequently “部”. It is concluded that the fundamental reason for the differences in meaning between the “一…… 半……” construction typified by the couplet with two five-character lines and the four-character “一……半……” construction lies in their different grammatical structures, the former being of a subject-predicate structure and the latter a coordinating structure.