In 1919, the March 1st movement began in Seoul and Pyeong’yang, and then spreaded to other regions throughout the Gyeong’gi-do province as well. The aim of this article is to examine the Japanese colonial authorities’ response and oppression of the movement, through cases of individual areas of the time. In the Gyeong’gi-do province, the Colonial authorities mobilized not only the Military Police and ordinary civil Police force, but also a so-called Self-defense squad (called “Ja’wi-dan”) composed of Japanese individuals who were living in Joseon at the time as well, in order to forcibly and effectively suppress the protesters. Colonial authorities also organized Inspection units (named “Sachal-ban”) to monitor public opinions of the Korean population, situation surrounding the religious sects, and foreign missionaries’ operations currently underway in Joseon.BR Coming into April, the Joseon Governor General office began to organize Self-defense squads with not only Japanese but also influential Korean figures known throughout the country. These Korean squad members were instructed to appease the Korean public and weaken the Manse protests in the process. Since April 13th, in the Gyeong’gi-do province, such Korean squads were organized in Su’weon-gun, Jin’wi-gun, Anseong-gun, Gang’hwa-gun and Go’yang-gun. The colonial authorities in Gyeong’gi-do also selected one or two local influentials from each of the Gun(郡) units, and assigned them to the task same as that of the squads. This shows us the fact that the colonial authorities’ method was shifting from ‘ex-post facto suppression’ from aggressive ‘beforehand prevention.’BR Meanwhile, the Governor(Jang’gwan) of the Gyeong’gi-do province requested the Japanese army be dispatched, so the 78th and 79th Regiments began sending over 830 troops to 26 areas inside Gyeong’gi-do. In order to intimidate the Korean public, the Japanese army would march down the street or conduct large-scale inspections in areas heavily populated by Koreans. Since March through June, there were over 60 cases of armed suppression in Gyeong’gi-do alone, and from at least 6,000 to 19,700 Korean souls were either injured, killed or arrested by the Japanese colonial authorities. The Provost Martial and Police Commissioner of the Gyeong’gi-do province requested that the police force in the area not be reduced, arguing that ‘The longing for independence embedded in their[the Joseon people] minds would never go away.’