Objective: Describing the knowledge, attitude and behavior of the risk of HIV transmission from HIV/AIDS persons, on the basis of suggest those intervention, the authors have promoted the interfered measures. Subject and method: A cross-sectional descriptive study on 125 HIV/AIDS transmitted people who have been managed at the health center of Chi Linh commune in Hai Duong province from April to October 2012, about the knowledge, attitude and behavior risks of HIV/AIDS infected people before and after exposure to HIV/AIDS. Result: Knowledge, attitude and behavior of HIV / AIDS transmissed people: Only 48 percent persons have adapted knowledge of HIV/AID transmission ways, 0.8-5.6 percent ones misunderstanding about HIV/AID transmission ways, 20.2 percent suppose that they do not have the risks of transmission for others, 16.6 percent ones do not know and 62.4 percent ones are not aware of risks. The behavior risks of transmitted people: There are 67 objects (53.6 percent) in the research has ever used drug, now 19 objects remained (30.4 percent) have been needling drug. The proportion of reused needles (BKT) is 25.4 percent, 11.1 percent objects have given the needles for others using, 97 percent have been) sexual intercourse (sex) in the past 12 months, with wife/husband/lover (89.6 percent), with caves 33.6 percent, with a casual partner 21,6 percent and playing with their clients is 3.2 percent. The highest proportion of condom use (BCS) in the recent time has been 76.6 percent and the lowest proportion has been 35 percent for clients. The reason for not using condom has not been here is (14.3-50 percent), disagreed lovers (9.1-50 percent), dislike use (0-42.9 percent), non-necessary (16.7-57 percent), which depends on each of object group. Conclusion: the authors have needed to enhance agitation and education for the HIV/AIDS transmitted to help them change their behavior. The authors have needed to strongly push and deploy the interfered program which reduce the harmlessness, concentrating on highly transmitted objects by supplying injection needles, condoms.