No evidence yet exists for the presence of early hominids in Cambodia, as it does for Indonesia and China, but it is known that by at least 38,000 B.C.Homo sapiens is moving through or into Cambodia. Exactly where these first inhabitants came from is not known for sure; whether from Malaysia or Indonesia, Vietnam or China, or some other region, they are probably not a Mongoloid people but are instead Australo-Melanesians, the short, darker people who inhabit parts of Southeast Asia at this time. Certainly other peoples moved into Cambodia in the ensuing millennia, and again their exact origins are not known. By about 13,000 B.C. the inhabitants of Cambodia are beginning to participate in the cultural developments occurring around them in Southeast Asia; they will continue to do so for the next thirteen thousand years. Cambodians will later fill in these early years with myths, legends, and folktales about their fabulous ancestors, but archaeologists and historians are not able to do much better when it comes to details. It is believed that the direct ancestors of today's Khmer arrive in Cambodia only about 200 B.C., and not until about the first century A.D. do the Khmer people of Cambodia appear to set themselves apart from the Funanese and Chams who live around the delta region of the Mekong River. By the end of the first century A.D. much of southern Cambodia will fall under the influence of the Funanese, and it is as the kingdom of Funan that Cambodia first enters history.
13,000–4000B.C.: The earliest known culture in Cambodia is the Hoabinhian, so named after the site in northern Vietnam where it was first discovered, Hoa Binh. This Hoabinhian culture, which is found across much of Southeast Asia, west to Burma, and north into southern China and possibly to Taiwan, is best distinguished by its tools: flat river pebbles of varying shapes but usually about fist size, flaked on one or both sides but with cutting edges around their entire circumference. The Hoabinhians forage and hunt for most of their food; although not agriculturists, they may have taken some trouble to encourage such native plants as yams and taro.