Originating in what is now southern China and northern Vietnam, the Vietnamese people pushed southward over two millennia to occupy the entire eastern seacoast of the Indochinese Peninsula. Ethnic Vietnamese constitute about 90% of Vietnam's 77.3 million population.

Vietnam's approximately 2.3 million ethnic Chinese, concentrated mostly in southern Vietnam, constitute Vietnam's largest minority group. Long important in the Vietnamese economy, Vietnamese of Chinese ancestry have been active in rice trading, milling, real estate, and banking in the south and shopkeeping, stevedoring, and mining in the north. Restrictions on economic activity following reunification in 1975 and the subsequent but unrelated general deterioration in Vietnamese-Chinese relations sent chills through the Chinese-Vietnamese community. In 1978-79, some 450,000 ethnic Chinese left Vietnam by boat as refugees (many officially encouraged and assisted) or were expelled across the land border with China.

The second-largest ethnic minority grouping, the central highland peoples commonly termed Montagnards (mountain people), comprise two main ethnolinguistic groups--Malayo-Polynesian and Mon-Khmer. About 30 groups of various cultures and dialects are spread over the highland territory.

The third-largest minority, the Khmer Krom (Cambodians), numbering about 600,000, is concentrated near the Cambodian border and at the mouth of the Mekong River. Most are farmers. Other minority groups include the Cham--remnants of the once-mighty Champa Kingdom, conquered by the Vietnamese in the 15th century--Hmong, and Thai.

Vietnamese is the official language of the country. It is a tonal language with influences from Thai, Khmer, and Chinese. Since the early 20th century, the Vietnamese have used a Romanized script introduced by the French. Previously, Chinese characters and an indigenous phonetic script were both used.