A modified version of the WHO/AIDS KABP Questionaire’was administered to 444 cargo ship’s crew and 55 passenger ship’s crew. The result showed that most of them had basic AIDS-related knowledge, but the knowledge about preventive measures was insufficant and misconceptions about the transmission of AIDS was widespread, nearly half of them thought that AIDS could be infected by mosquito bites or kiss, and 9% of them thought that AIDS could be infected by dancing or shaking hands with AIDS patients. 15.6% of the cargo vessel’s crew and 11.1% of the passanger ship’s crew didn’t believe those infected with HIV might appear healthy. There were 62.2% of the cargo vessel’s crew and 75.5% of the passanger ship’s crew who had sexual experience had used condoms, but 40% of them didn’t believe the protective effect of condoms. A negative association was found between knowledge level about AIDS and some AIDS-related high risk behaviours. 14.8% of the crew admitted that they had multiple sexual partners, 4.4% of the crew ours out of mainland, 2.2% of cargo vessel’s crew had history of drug injection. The group who had multiple sexual partners expressed less fear of being infected with HIV(P<0.01), they also had stronger tendency to have sexual behaviours with the casual partners without condoms (P<0.01). A modified version of the WHO/AIDS KABP Questionaire’was administered to 444 cargo ship’s crew and 55 passenger ship’s crew. The result showed that most of them had basic AIDS-related knowledge, but the knowledge about preventive measures was insufficant and misconceptions about the The transmission of AIDS was widespread, nearly half of them thinking that AIDS could be infected by mosquito bites or kiss, and 9% of them thought that AIDS could be infected by dancing or shaking hands with AIDS patients. 15.6% of the cargo vessel’s crew and 11.1% of the passanger ship’s crew didn’t believe those infected with HIV might appear healthy. There were 62.2% of the cargo vessel’s crew and 75.5% of the passanger ship’s crew who had sexual experience had used condoms, but 40% of them didn ’t believe the protective effect of condoms. A negative association was found between knowledge level about AIDS and some AIDS-related high risk behaviours. 14.8% of the crew attended that they had multiple sexual par Tners, 4.4% of the crew ours out of mainland, 2.2% of cargo vessel’s crew had history of drug injection. The group who had multiple sexual partners expressed less fear of being infected with HIV (P<0.01), they also had stronger tendency. To have sexual behaviours with the casual partners without condoms (P<0.01).