Objective To investigate the sexual behavior, knowledge and attitude toward sex of soldiers in remote islands in extraordinary environments. Methods Two surveys were conducted on 354 soldiers on their tour of duty on the Spratly Islands. The surveys inquired about the soldiers’ sexual experiences before and 3 months after being on the islands to determine their testosterone levels. Results Our survey shows that masturbating is very common with island soldiers. They can easily accept it, have fun and relax from it. Environmental factors have direct effects on their sexual attitude — the tougher the situation they are in, the higher the masturbation rate. Their testosterone levels 3-month after being on the Islands is obviously higher than before being on the Islands (P<0.001). The survey also indicates that soldiers on the Islands can easily understand and are tolerant of sex without marriage. However, when choosing a wife/husband, they pay more attention to the inner quality of their mates, instead of economic status, social position, and family background. Island soldiers gain their sexual knowledge mainly from medical books/magazines, sex exhibitions and their same-sex friends. Lectures, consulting hot lines and exhibitions are the three educational ways they like most.Conclusion Sex education, including but not restricted to peer education, self-control, as well as moral value classes should be given to soldiers on the Spratly Islands to ensure their good physical and mental heath. Objective To investigate the sexual behavior, knowledge and attitude toward sex of soldiers in remote islands in extraordinary environments. Methods Two surveys were conducted on 354 soldiers on their tour of duty on the Spratly Islands. The surveys inquired about the soldiers’ sexual experiences before and Three months after being on the islands to determine their testosterone levels. Results Our survey shows that masturbating is very common with island soldiers. tougher the situation they are in, the higher the masturbation rate. Their testosterone levels 3-month after being on the islands is obviously higher than before being on the islands (P <0.001). The survey also indicates that soldiers on the Islands can understand and are tolerant of sex without marriage. However, when choosing a wife / husband, they pay more attention to the inner quali ty of their mates, instead of economic status, social position, and family background. Island soldiers gain their sexual knowledge mainly from medical books / magazines, sex exhibitions and their same-sex friends. Lectures, consulting hot lines and exhibitions are the three educational ways they like most.Conclusion Sex education, including but not restricted to peer education, self-control, as well as moral value classes should be given to soldiers on the Spratly Islands to ensure their good physical and mental heath.