Child sexual abuse (CSA) is estimated to be prevalent. Prior studies based on adult or college-aged women recalls of their childhood or adolescent experience of sexual abuse reported the prevalence ranged from 10 to 50 percent depending upon study samples and instruments of measuring CSA (1-9). When many women were asked about their lifetime experience of sexual abuse, first abuse was reported mostly to occur during childhood or adolescence (before aged 18) (10, 11). These studies are, however, subject to unreliable recalls of long delayed, adult retrospective accounts of sexual experience and particularly, may also miss substantial numbers of individuals with such abuse history (12). Compared to adult studies, there are fewer studies to report the rates of sexual abuse in adolescents in the US (13-18). A recent report found that 21 percent of adolescents aged 14 to 18 years were ever forced to have unwanted sexual intercourse (13).