Objective To evaluate the efficacy and security of long-term orthokeratol. in myopic adolescents. Methods A retrospective case series observation study was adopted. Totally one hundred and fifty-three patients(153 eyes) of juvenile myopia who were wearing orthokeratol.(ortho-k) lens for five years were chosen between Jan. 2012 and Dec. 2013 from Tianjin Eye Hospital Optometry Center. The health of cornea, axial length, central corneal thickness(CCT), corneal endothelial d., percentage of hexagonal cells and the coefficient of variation were measured before and after 1 yr, 2 years, 3 years, 4 years, 5 years of wearing ortho-k lens. All parameters were tested by normal test and evaluated by repeated measurement one-way ANOVA. Results There were significant differences in uncorrected visual acuity and spherical equivalent before and after wearing an ortho-k lens(F=442.515, 415.389, both P<0.001). The axial growth rate of myopia was 0.16 mm per yr. During 5 years of ortho-k lens wearing, 64 eyes(41.80%) developed complications of varying degrees, among which 70.31% had mild grade 1, 2 corneal epithelial staining. Compared with the CCT before lens wearing, the CCT was slightly thinner at each follow up time(all P<0.001). There were no significant changes in the corneal endothelial d. and the average area of endothelium before and after 5 years of wearing the ortho-k lens(F=0.328, 0.735, both P>0.05). However, the hexagon ratio of endothelium was significantly decreased(F=12.020, P<0.001) and the coefficient of variation of corneal endothelium was significantly higher(F=23.016, P<0.001). Conclusion Wearing ortho-k lens for a long period of time in adolescent myopic patients can obtain good uncorrected visual acuity and effectively delay the growth rate of axial length without serious corneal or conjunctival complications. There is little effect on corneal endothelium and central corneal thickness.