This study aims to furnish basic data about prevention and infection control of Hepatitis B Virus(HBV) for those who, working in dental offices, are particularly exposed to a high risk of HBV infection. A survey was conducted to 310 students including freshmen, sophomores and juniors enrolled in the dental hygiene department in order to examine their knowledge about infection routes of HBV, clinical history of their family members and their own health. The outcomes of the survey showed following facts; 1. Students were found to lack knowledge about the present conditions of their HBsAg and HBsAb of HBV(PF0.05), conduct of preventive vaccination(PE0.05), completion of 3 required vaccinations(PF0.05) and formation of antibody(PF0.05). 2. Students named "blood"(88.6%) and "infected needles"(82.5%) as most likely infection routes of HBV(PE0.05 and PE0.01). These replies came mostly from sophomores(65.6% and 92.1%), followed by juniors(89.2%, 82.5%) and freshmen(81.1%, 73.0%). Least knowledge about infection routes of HBV was sensed with the reply "infection through breast-feeding of positive mother(27.9%)"(PE0.05). Generally, sophomores seemed to have much knowledge about infection routes, followed by juniors and freshmen in order. 3. As to clinical history of family members, 10 students(3.5%) replied that any of their family members is suffering from HBV now, 8(2.6%) revealed that some of their family members once suffered from it and 10(3.2%) reported cases of death of their family members from liver diseases. 4. Ninety-four point seven percent of respondents believed their health to be better than normal.