PURPOSE: A sex crime preventing apparatus, a system and a method thereof are provided to prevent sex crime in advance, by performing concentrated management for sex offenders in which a bio-signal of abnormal state is continuously detected, by judging crime intention of the sex offender through the bio-signal as being linked with the position of the sex offender.CONSTITUTION: A sex crime preventing system includes a management server (200) and a sex crime preventing apparatus (100). The management server manages sex crime. The sex crime preventing apparatus is worn at a part of a human body of a user. The sex crime preventing apparatus includes a communication part (140), a pulse measurement part (120), a global positioning system (GPS) part (110) and a control part (130). The communication part communicates with the management server through a communication network. The pulse measurement part measures pulse value of a user. The GPS part provides position information of the user. The control part transmits the position information and unique identification information to the management server through the communication part, and compares the pulse information with a pre-established pulse range, and transmits the position information and the pulse information to the management server through the communication part by changing transmission period which is pre-established in correspondence to the step including pulse information. The management server classifies a sex offender and a general user through the unique identification information by receiving the position information and the pulse information, and provides position information of the sex offender and the general user to a registered portable terminal by searching the position information of the sex offender whose distance from the general user is within a pre-established distance.COPYRIGHT KIPO 2013[Reference numerals] (110) GPS part (120) Pulse measurement part (130) Control part (140) Communication part (15
