Examined in this article, is essentially the usability that a research methodology dealing with 'concepts' could have as an analytic approach in studying Korea's colonization during the Japanese occupation period. In this article, statistical data regarding terms and concepts will be mainly dealt with. And it will be attempted to develop a comprehensive and effective method of analysis concentrating upon both the issue of quality and quantity, and employing both synchronic and diachronic approaches. Total of 199 types of terms related to the concept of 'mass' are extracted from journals and bulletins such as Gae'byeok , Byeol'geon'gon and 『Samcheon'ri』. In processing them, first, terms which showed considerable shifts in the frequency of their usage were assorted into two groups, namely the ‘Social movement' group and the 'Popular culture’ group. And in consideration of time periods displayed in the usage of terms that belonged to those groups, three time periods were established, which could be respectively labelled as the 'Social movement concentration period,' 'Period of two phenomena in juxtaposition,' and 'Popular culture concentration period.' Second, putting the apparent trend aside for the moment, it should be noted that 'general(全稱)' terms which showed very little changes in the frequency of usage could be regarded as showing the most substantial or even fundamental flow of changes in the usage of 'mass'-related terms, so they were examined with details in this study as well. And third, to fill in the blanks that could be still remaining, the historical meaning of the four critical time points are discussed as 'wordfield('意味場')', and are elaborated upon as well. It was an attempt to secure a synchronic approach, which could complement the diachronic approaches attempted in the first and second tasks. In the first period(1920~1925), the Socialists rather led the usage of the 'mass' concept, in order to set it apart from the 'people(民衆)' concept that had been widely used since the outbreak of the March 1st Movement. Yet at first, they did not use the term as an independent concept. They rather used it in association with another concept, like 'Proletarian.' Moreover, they failed to integrate the term with a Socialist aspect and establish it as a term describing a 'subject engaged in a cause or movement.' This period clearly shows an infant stage in terms of embracing a concept. In the 2nd period(1926~1933), the ‘mass' concept escaped the confinements of referring to only the 'Proletarians,' and began to be used in various meanings, and in many cases the concept was used in positive terms as 'entities associated with social movements.' During this time period, in the wake of discussions debating whether to dissolve the Shin'gan-hwe party(新幹會) or not, the term that was most prominently used switched from 'Proletarian mass' to 'mass of Peasants and Workers', transforming the concept from merely referring to the general Proletarian class to referring to the agricultural and industrial workers in particular. Meanwhile, in this time period the concept already started to emerge not only in the 'social movement' context but also in the 'popular culture' context as well, yet such new phenomenon was not yet distinct enough to be mentioned with regard to the historical meaning of year 1931. In the 3rd period(1934~1942), the time before the China-Japan war and the time after the war showed some differences. Before the war, terms in league with the 'popular culture' group were more frequently used, reflecting the growth of the urban popular culture and the dissolution of the Shin'gan-hwe party. Then after the war, and when the so-called 'Wartime Mobilization period' began, the concept of 'mass' was practically rendered meaningless. Instead, a new concept of ‘state citizen(국민)’ surfaced, while the 'people' concept began to be frequently used again.