This essay adopts a research approach of the historical/political science, emphasizing the application of concepts of the political science to historical studies. The documental analysis is taken as a method to explain the causes and effects of the formation of the Taiwan Mass Party (TMP). This essay starts from a point arguing that Japan, a premature junior capitalist empire, enforced a coercive and suppressive rule as an instrument of Old Colonialism over her colonial Taiwan to serve the will of the empire. For accommodating to the ambition of the empire, the Japanese colonial government established its stable ruling groundwork by double means of political and societal control over Taiwan. In the aspect of political control, a colonial policy of "Ethnic Different Treatment" was executed; in that of societal control, a dependent policy of assimilation. Under the oppressive rule of Japan, the Taiwanese carried out their armed and non-armed anti-Japanese activities, both reflecting evident elements of nationalism. The former lost their battles due to lack of political ideologies with faith, advanced weapons and organizations for military training. However, the latter brought about profound and widespread influences by organizations of mobilization uniting classes of workers and farmers to proceed their struggles under the leadership of local elite who received new-styled education. During the process of non-armed anti-Japanese activities, the Taiwan Mass Party, the first modem party with organizational functions, was born. Moreover, this essay reviews the historical conditions of occurrence of the TMP with core concepts such as "crisis" and "modernization" in Theories of Historical Situations and Development regarding the research on the origins of parties. Furthermore, the 6W concept and the party categorical systems are applied to explore the character of the TMP, certifying that the TMP was an externally-created, limited, caucus-styled, power-centralized, anti-established, quasi-revolutionary nationalist party. Finally, this essay analyzes the influences and meaning of the party formation movement of the TMP during the historical development from political, cultural and socio-economic aspects.