A cross-sectional, direct-interview study on 800 people (395 males and 405 females) of Dao ethnic population from 15 to 49 years of age in Van Chan District, Yen Bai Province showed that: Regards the education: none university/college, vocational school (0.5 percent), high school (1.1 percent), secondary school (24.6 percent), primary school (32.3 percent), illiteracy eradication (4.9 percent), and illiteracy (36.6 percent). There were 49.6 percent and 46.5 percent of the sample comprehended at reading and writing of national language, respectively. The median age of first sex was 17.0. Among the group of 15-24 years-old, the prevalence of first sex before 15 years-old and premarital sex were 1.4 percent and 56.3 percent, respectively. There was vas difference of comprehensive knowledge of HIV/AIDS transmission routes and prevention across education groups (mean = 11.2 percent). The prevalence of condom use in sexual intercourse in the past 12 months was low: 25.8 percent used condoms in the most recent sexual intercourse with husbands/ spouses and 11.6 percent always used condoms in every sexual intercourse. 24.9 percent of the sample had sexual intercourse with casual partners in the last 12 month, of which there were 52.7 percent and 21.2 percent using condoms in the most recent and in every sexual intercourse, respectively.