In recent years most of criminologists in Korea have worried about sex crimes, especially rape and sexual harassment. Whereas many studies on rape and sexual harassment have published and their countermeasures have established, there are few papers related to sexual deviance other than rape and sexual harassment. We think our sexual practice to be normal. But many forms of sex behaviors are beyond the realm of what many consider normal, and some are even illegal. In this paper, I review and summarize several forms of sexual deviance and sex crimes(problems) using literature review on previous research published in the United States recently. At first, I examine the seriousness of sexual deviance and related problems in Korean society. Secondly, I examine the definition and sorts of sexual deviance such as exhibitionism, fetishism, frotteurism, pedophilia, masochism, sadism, transvestic fetishism, voyeurism and psychosexual disorder not elsewhere classified under the DSM-Ⅳ. Thirdly, I review the five major sexual deviance and their crimes(problems); ① pedophilia and related crimes, ② sadomasochism and related crimes, ③ exhibitionism․voyeurism and related problems, ④ homosexuality and related problems, ⑤ sexual addiction and related problems. Most people cannot understand how someone can fatally assault a child. Perhaps even more appalling in the United States is that national organizations exist that lobby for the legalization of sex with children. Although individuals and sadomasochistic sex scenes have received some attention, little interest has been paid to the social conditions producing this behavior. Sadomasochistic practice such as spanking, bondage, humiliation and body modifications are obviously serious crimes. Research on exhibitionism․voyeurism on the Internet should appear soon. Researchers already have noticed the widespread practice of people entering chatrooms in cyberspace to discuss sexual interests and desires. Homosexual individuals and groups are found everywhere in different guises. Homosexuality are even in fashion in Korea recently. Sexual addiction, often also referred to as sexual compulsivity, has an unusual definitional status. But this practice are in fashion mediated by pornography, Viagra, aphrodisiacs and contraceptives. Finally, I summarize the results of the study and suggest several policy implications.