==Tahun 1940-an hingga 1950-an: Pendirian Partai==
DuringSelama itstahap initialawal phase of existencekeberadaannya, thePartai CommunistKomunis PartySiam oftetap Siammenjadi remainedsebuah apartai smallkecil, party.yang Itterutama wasberbasis mainlydi basedkalangan amongstintelektual intellectuals indi [[Bangkok]] anddan the servicesdinas. ByPada earlyawal tahun 1948, sumber-sumber intelijen [[UnitedBritania KingdomRaya|BritishBritania]] intelligencemenganggap sources"berlebihan" deemedlaporan reportsyang thatmenyatakan thebahwa partypartai wouldtersebut have hadmemiliki 3,.000 members nationwideanggota assecara 'exaggerated'nasional.<ref name="ari">[http://www.ari.nus.edu.sg/docs%5CColdwar-project%5CCommunism-in-the-FarEast-JNedited-web.pdf Report 12 of 1948 by the Joint Intelligence Committee (Far East)]</ref> ThePartai partyini enjoyedmenikmati aperiode brieflegalitas period ofsingkat legalitydari fromtahun 1946 tohingga 1948.<ref name="factors">Stuart-Fox, Martin. [https://www.jstor.org/stable/2643855 Factors Influencing Relations between the Communist Parties of Thailand and Laos] in
Asian Survey, Vol. 19, No. 4 (Apr., 1979), pp. 333-352.</ref> TheMarkas secretbesar partypartai headquartersyang wererahasia locatedterletak indi asebuah woodenbangunan buildingkayu atdi [[Jalan Si Phraya Road]], [[Bangkok]].<ref>[http://www.asiapacificms.com/articles/chin_peng/ Book Review: From Decorated Hero to Public Enemy No. 1 - Asia Pacific Media Service<!-- Bot generated title -->]</ref>