The history of Phnom Penh City was at least 500 B.C. Phnom Penh city is considered to be a new city, governed by King Chau Ponhea Yat in 15th century. The discovery of society achievement at the time such as Metal bell, Ceramics and the round city around Choeung Ek has changed this theory. Based on these historical accounts; we can conclude that this site used to be a cultural hub at the period of at least 500 B.C. In conclusion, the prehistoric measurement of Phnom Penh City is proven for the first time by archeology.