In this article the problem of the penetration westwards of Iron Age Oc Eo culture (1 <sup>st</sup>-7 <sup>th</sup> centuries CE) is seen in the light of the archaeological material from Phum Snay site in north-western Cambodia, which has been excavated and is being researched by the author. The inventory of this necropolis demonstrates close typological similarities with the objects of Oc Eo culture in the Mekong Delta. Such similarities can be seen not only in luxury goods but in ordinary objects as well. This makes us suppose the penetration of Oc Eo culture far to the depth of the continent that is important for the further understanding of the genesis of Khmer culture and the state. In the same time, richness and diversity of the archaeological material in the Mekong Delta, comparing to inner regions let me suppose that Delta was the center of this culture.