1946年中共地下黨組織「臺灣省工作委員會」領導機構移轉來台，以蔡孝乾為書記、張志忠與洪幼樵為委員，負責從事顛覆國民黨政權的工作。 本文嘗試將研究範圍限縮在台北市地區，時間斷限在1946年~1950年，微觀地爬梳台北市地下黨組織、策略、黨員三方面在「二二八」事件前後的發展狀況。 「臺灣省工作委員會」在台北市的黨員基礎，最初是透過舊臺共份子如廖瑞發、林良材等人的關係拓展開來，再逐步深入社會、校園。臺北市地下黨組織系統有市級與省級兩類，市級系統為「臺北市工作委員會」下轄「台大附屬醫院支部」、「臺北市司機工會」、松山第六機廠支部等，省級組織則包含新聞記者工作小組、「山地工作委員會」、「臺灣郵電總職工工作委員會」等。 本文研究結果發現，在「二二八」事件發生後到1950年蔡孝乾宣布解散「臺灣省工作委員會」這段時間，是臺北市共黨人數激增的高峰期。而這些人多屬臺籍，具有相當濃厚的地域色彩，且年齡集中在20~50歲的青壯年階層。社會階級則多分布在知識青年與工人兩類，中產階級、農民階級反倒少見，因黨員屬性的侷限，導致地下黨工作一直侷限在「左翼」、「共產」思想的啟蒙工作上，反倒甚少從事實際的顛覆工作。 The Taiwan province working committee organization of the Chinese Communist Party（CCP） was moved in 1946.The secretary was Tsai hsiao chien, and Chang chih chung, Hung yu chiao were the committee members , to subvert the KMT government. The objects of study in this paper are defined in Taipei city region between 1946~1950. There are three parts to be studied in this essay which are organization, strategy and party members vary around 228 massacre. The party members of Taiwan province working committee organization in Taipei city area are extend from the Taiwanese Communist Party（TCP）relationship , and next develop enter the campus with society. the organization of the Taiwan province working committee in Taipei city area are Taipei city working committee , University of Taiwan Hospital branch, the drivers trade union of Taipei city, the Sungshan sixth factory, the Newsman working group, the Indigenous people working committee, and the Taiwan post office with telegram working committee etc.
The conclusion of this essay：
1. the party members quantity increase peak are between 1947~1950 2.the party members mostly are Taiwanese, it is localization. 3.these members are young adult, their age distribution is within 20~50.
In addition, all party members in Taipei city area mostly are educated youth, intellectuals and worker but farmers and middle class. Above-mentioned cause the party must concentrates in socialism thought initiation but practical work.
